You Need To Know About This Number
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- เผยแพร่เมื่อ 16 มิ.ย. 2024
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Hi 🤓
Hai sir nice video
I've got it :0
Nice video!
CANCEL REPLY
Hey Bri, thanks for the awnsers. Some of the math questions were actually from my homework lol. So um thank you! Btw nice content.
POV: you're messing with your calculator during math class
th-cam.com/video/b1fXcnnCAbA/w-d-xo.html
never gonna give you up
80085
*lmao*
@@alvinalpha_seven5330 never gonna let you down
another interesting fact about 108 is that the numbers from lost (4, 8, 15, 16, 23, 42) add up to 108, which also happens to me the amount of time on the clock in the hatch controlling the electromagnetic bomb
Cool!
Lost?
@@RubyPiec yeah just a trash tv show
Lost? *The comic strip?*
The numbers XD
343 is my favorite number. Back in high school I memorized all of the cubes of the numbers 1-10 for the heck of it, and for some reason the fact that 7 cubed was such a beautiful looking number stuck with me. Especially since I've always kind of hated multiples of 7 because there's no easy trick to identify if a number is divisible by 7 without just checking, unlike other single digit numbers which all have at least something that would give you an idea if they could possibly divide evenly into a number.
343 is also my favorite number! Good choice
There's actually a way to check divisibility for 7 if I am not wrong.
For example, let's take the number 2744, and try and find if it's divisible by 7 or not. Then, take the last digit, i.e. 4 and the remaining number is 274. Then double the digit that you removed and subtract it from the original number. 274 - 2(4) = 274 - 8 = 266.
Now, repeat it for 266, 26 - 2(6) = 26 - 12 = 14.
At the end, if you end up with a 0 or a multiple of 7, the number is divisible by 7.
It's a bit lengthier compared to the other divisibility rules, but it works.
Scp-343 is also fricking GOD
halo
It’s also around the speed of sound in air
Oh, and also:
13^2=169 and 31^2=961.
144 and 1444 are perfect squares, as are 576 and 5776.
Thanks for explaining these numbers - I'm a mathlete, so that 142857 rang a bell.
That first fact of yours is kinda trivial, the second one's cool though.
@@micahmeneyerji property of 11
U might find this interesting:
th-cam.com/video/BDZ53An3g_o/w-d-xo.html
bruh
@@serulu3490 what does 113 have to do with 11?
Fun Fact: The first number with no a single interesting property is (actually I forgot the number), but since it is the first number with no interesting property, that is a interesting property by itself.
By that logic, we can be confident saying that no number is boring
@@Rudxain what happens when we hit the second uninteresting number?
dude now i want to know what the number is
@Puppo nice
did you remembered it?
It hurts that I had to discover this for myself this year but I just had to share it...
The number 2021 is the product of two consecutive prime numbers (43*47). The last year whose number had this property was 1763 (41*43) and the next will be 2491 (47*53).
On that note, here's a friendly reminder that this year, we're just as far from 2017 as we are close to 2027, which also happen to be the two closest prime numbers to 2022. So I guess this year isn't all that boring!
2022 = 2^2 + 9^2 + 44^2
*2021
@@locomotivetrainstation6053 all you need to do find that is just find prime factors of this number and accordingly arrange them in the way you want.
Who else discovered the 142857 themselves. You just have to play with the number 7 for some time to notice this.
I actually discovered something more general from numbers like this:
(10^a )/b - 1 always has special properties
For instance
(10^a)/b - 1= c*d then 1/c has the same numbers as d*a^n spaced a digits apart. i.e, 100/2 - 1 = 49 = 7*7
1/7 = 0.14285712 (57 because 56 + 1.12)
7*2 = 14, 7*4=28, 7*8=56, 7*16 = 112…
@@jacobpaniagua8785 That's so cool.
lucky number 7
Pretty sure I saw something similar when dividing by 13, just with two number combinations instead of one.
Pattern 1: 076923
Pattern 2: 153846
1/13 = 076923 (1)
2/13 = 153846 (2)
3/13 = 230769 (1)
4/13 = 307692 (1)
5/13 = 384615 (2)
6/13 = 461538 (2)
7/13 = 538461 (2)
8/13 = 615384 (2)
9/13 = 692307 (1)
10/13 = 769230 (1)
11/13 = 846153 (2)
12/13 = 923076 (2)
I still have no idea why this works or why there doesn't seem to be a consistent pattern
19 and 23 work too…
As soon as 142857 popped up, I thought, "Hey look! It looks like 1/7!"
Also, for 6174, you said that should work with any four-digit number without repeating decimals, but it did not work for the first two. Under what conditions, then, does it work?
He means if you iterate the process a sufficient amount of times, you eventually arrive at 6174
Any four-digit number without repeating decimals. He said it works if you do it over and over, and it does. Within seven steps, you obtain 6174
3 digits gives you 495 by the way
i thought you meant 7 factorial for a moment, that's why you should be careful when using exclamation marks and math at the same time lol
Fun fact: numbers like 142857 are called carousel numbers and are related to primes. If the decimal expansion for 1/p has p-1 repeating digits then that p-1 digit number has the same cyclic property mentioned here. The next such number occurs at 1/17. Try it!
2:55 Something else I noticed:
7 × 2 = 14
7 × 4 = 28
(7 × 8) + 1 = 57
1/7 = 0.142857 (it repeats)
And here is 142857.
I noticed that too
For 1/7: 0.142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857...
infinite.
0.(142857) rec/bar
x/7 = _________.142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857142857...
I love how the eight is styled at 5:28 so it isn't horizontaly symmetrical
Nice video! A lot of these interesting numbers poped up in Project Euler problems (e.g. cyclic numbers)
Interesting!
@@BriTheMathGuy Do you know much about these kinds of numbers in other bases? I’d love for you to do it with base six!
I am being haunted by the number 225. Back when I learned programming in C in university (where you can't normally use characters that aren't part of the ascii table), I made a list with the code for some characters I might want to use more often. Like the german ß (an alternative for "ss"), because my name contains it. Guess what number I remembered? Right it's 225. That's when it all began.
Now I see it everywhere. in calculations, because 1.5² equals 2.25,
in trigonomitry, because 5/4 of pi is 225°, while 1/8th of pi is 22.5°,
I frequently look at random clocks, only to find out it's 2:25, 12:25, or any of the 22:50s.
Almost every time a timer runs down somewhere in my line of sight, you can bet I randomly look at it, exactly when there are 2 minutes and 25 seconds left.
The list goes on. I'm telling you, this number pops up everywhere!
I read this comment and saw the time on this video at that instant. It is 2:25 🤐
@@moonandtanu7591 now the 225 is coming for you aswell
what are you leaning to program
@@blackpeople6874 I lerned programming in C in first and second semester and Java in third semester.
Rush ß
5:50
"Except for 998"
I think that's because the number 998,001 already has a 998 in it.
001 is also in 988.001 but it is listed in the result.
The real reason is carryovers. 1000 is four digit but can only occupy thre spaces so there is a carryover turning 999 into 1000, which again creates a carryovers turning 998 into 999
…
1/7 = 0.14825 *7*
@@gallium-gonzollium wrong it is 0.142857... you messed up the order of 2 and 8
Best numerical educational video ever! Great job breaking it down
This video is SO satisfying.
Thank you very much.
You forgot most of the properties of 142857.
Split it in two, and sum the parts: 142 + 857 = 999
Split it in three, and sum the parts: 14 + 28 + 57 = 99
Square it, split it in two and sum the parts: 142857² = 20408122449, and 20408 + 122449 = 142857
How to easily remember this number? It's simply the decimal part of 1 / 7 (which is why 142857 * 7 = 999999).
There are some even more interesting properties.
142857 is the repeating digit sequence associated with 1/7. 1/7 is exactly equal to 0.142857 repeating. Additionally, you will note that each set of 2 digits is exactly double the previous 2. Except for 57. This is double plus 1.
This is because the next set of 2 digits becomes 112. And the 1 carries over, to turn 56, into 57. Likewise, the "12" in "112" carries over to become 14 as the 2 from 224 carries over.
This continues on no matter how far down you go. If you continually double the multiple of 14 all the way down to infinity, the numbers will get farther and farther away, but, the digits that carry over will always self-correct back to 142857.
Because of this, the decimal of 1/7 can actually be expressed in sigma notation. 1/7 is exactly equal to the sum of all values of n, from 1 to infinity, of (7*2^n)(10^-2n)
I've never watched a math video in my entire life on youtube, yet this has been stuck in my recommended for 1 week, finally clicked on it and wasn't dissapointed!
2:15 It's like I'm listening to Sheldon talking
I’ve never been interested in numbers facts, but this is fun, You just got a new subscriber! 😊
I saw the 142857 when I was 5 in the first math book my parents gave me. The book had a calculated attached to it, so kids could play with math and numbers and get hooked. Needless to say I got hooked and needed up taking a master in applied math 20 years later. Just finding the book now and are trying to show it to my 5 year old son.
for the 142857 thing i discovered this a few months ago when working with x/7 fractions a bunch, its really cool.
also x/13 has two different sets of numbers that are used in the decimals (076923 and 384615). therefore I'm pretty sure that 076923 is the smallest (whatever that word is at 2:52) number
smallest cyclic number
x/251 uses five of these strings of digits, each with a length of fifty digits!
Another fun fact for 76923, it can be cyclic when its multiplied by 3^x, try that at the calculator
Edit: also 12
Damn it. My x/7 comment was already taken, but I think I can explain a bit more about it.
1/7 is 0.142857 repeating.
2/7 is 0.285714 repeating.
3/7 is 0.428571 repeating.
You might see the pattern between this and the one in the video.
4/7 is 0.571428 repeating, just like 142857×4 is 571428.
Same thing can be applied for a lot of prime numbers
2:55 1/7 = 0.142857, cool, isn't it?
Great video as always, keep it up!
Thanks a ton!
Imagine someone finding all the beautiful and special numbers then on their way to find true rule of math
2:03 everyone knows this already from the big bang theory
whats the big bang theory
Very interesting! Math is cool, so much deeper than you first think!
6:40 e^(i*tau) = 1 is EVEN MORE beautiful. No need to fudge the equation.
Thank you... I just love numbers! Subscribed!
142857 is a series like 14, 28, 57. 14 * 2 = 28, 28 * 2 is really close to 57, 56 actually. The reason why this number is cool and cyclic is because it comes from (1 / 7 )* 10 ^ 5 (truncated at the end, it repeats indefinitely) When you do 2 / 7, or 3/7 so on so forth, because 7 is prime and it uses 6 individual digits, it makes a repeating pattern because there is nothing else it could be.
Does cool stuff like this also show up in other counting styles? (Like in duodecimal?)
My personal favorite number is 729 bc it’s 3^6 and when you make it 1/729 it will gives you the longest (in length) number I could find (only in some calculators are possible) and 1/729 is cyclic infinite number (which means that the number you’ll get from school’s calculator is 0.(00137.....)
Also don't forget on 4:22 that the angle between the center of a tetrahedron and two corners is about 108 degrees as well. The angle comes up a ton in chemistry because most carbon atoms are bonded to 4 other atoms in a tetrahedron.
Kaprekars constant actually works with a lot of numbers that have repeating digits, just not all
Optimus Prime: I'm everywhere.
3:02 if you divide anything by 7, you always get those numbers (in any order) infinitely in the decimals (unless there are no decimals)
I am questioning math
I love how you had to specify the space was Euclidean
Thank you very interesting
These all feel like creepypastas or something where they _mysteriously fit into place and are too perfect to be a coincidence_
at 1:17 3087 is 1/2 of 6174, which is also interesting
That was a coincidence I think
So you do Number Theory? Im curious where at...I did Repr Theory, Group, Rings, with a big interest in Hyperbolic Geom.
A lifetime ago...
153 is also the minimum rectilinear crossing number for 12 points.
1:18 sir i figured this out you could do this with repeated digits as well. Take for example 3996. I was able to do. But yeah this is the most mind-blowing math trick i have ever seen!
1:40 really proud of Mr. Ramanujan ❤️
142857 was due to the fact that 1/7 is equal to 0.142857 and when multiplied, it rearranges accordingly (a property of that fraction).
So far, this is my favorite video of yours
Glad you enjoyed it! Thanks for watching :)
153 is also a minimal length of a superpermutation of 5 district elements
I've kinda known that smallest cyclic number since HS. Those are the digits of the repeating decimal(s) of sevenths- 1/7= 0.142857, 2/7= 0.285714, etc.
Also adding cubes of the digits of multiples of 3, leading eventually to 153, I've encountered before. Now I can't recall if that is invariably true. I vaguely remember some infrequent solutions involving pairs of 3 digit numbers that oscillated, e.g. 261162.
Depending on the font, 108 also has vertical symmetry on each individual digit
Yeah like how i used to draw 1 in kindergarten just a l
@@Khadar2 it is also correct so you can still do that and I still do that
5:48 Since that one is true and which I never heard about, the original form is -1+1=0.
can you do mars's rotation around the sun please
It might not be that interesting, but my favorite number has always been 28. All it's factors add up to itself. Pretty simple, and it's a pretty small number, which makes it even more memorable for me.
Umm 6...
@@rafiihsanalfathin9479 6 is boring. 28 is Epic.
@@godlyvex5543 actually if 2^n-1 is prime number, then 2^(2n-1)-2^(n-1) have your favorite number property, ex: if n=5 then 2^n-1 is prime, so 2^9-2^4 have your number property (496)
n=7 works too etc
@@godlyvex5543 6 too small, 496 too large, 28 is perfect (a perfect perfect)
2:22 in the 73 if yo take the 7 multiplied by 3, that 7x3=21
I know most of these are just coincidences and a result of the base-10 number system, but it feels magical
The example with 73 shows us how you can find very cool properties with any number
5:10 Ah yes, a rectangular pentagon.
What
3:20 if you add the first 3 and the second 3 digits, you get 999
Because 1001 = 143*7. So 1001- 1.001 = 999.999 = 142.857*7.
the second i saw the thumbnail i KNEW adding one would be cursed af
Someone needs to make a PowerPoint presentation on these numbers.
That cyclic number has another interesting property. 142857
285714
428571
571428
714285
857142
Look at the numbers in the columns, reading downward. They form the same pattern.
Looks like only the first column does. The rest are scrambled.
@@TheRealEvab nope, not at all!
It's the same pattern, imagine writing 142857142857142857 and looking at all of those numbers. All of those numbers you will be able to find in the sane order but shifted by 1
I'm starting to like this number 142857. It's a trick of 7.
Also fun fact: probably what most people see first about 7 is that; it's a prime number, it's square is not divisible by any real number and 91 is not prime while 93 is (91=7×13)
@@Hagurmert If they meant the rows, then yeah. I thought they were meant going top-to-bottom. It's been a long time since I made my comment, though, and looking back, that first column is definitely not correct like I thought it was lol.
there's also 8833, which is equal to 88^2+33^2, yet compare to these featured in vid, that one's like a drop in the ocean
3:27 142857 is the repeating number in the decimal representation of 1/7 this is why when you multiply it by 7 it is so close to 1000000. (You can prove it with arithmetic)
127 is a Mersenne prime, its exponent (its binary length) is 7 which ALSO is a Mersenne prime, yet again its binary size is 3 another Mersenne prime. This means it's a triple _recursive_ Mersenne number, and a triple Mersenne prime.
However I'm kinda cheating, because for a Mersenne number to possibly be prime, its exponent MUST be prime, so all those exponents being prime is a requirement. I don't know if 2^127 - 1 is prime, I'll ask WolframAlpha.
*EDIT:* I asked Google and YES IT IS! 2^127 - 1 is prime! It's the only known quadruple M-prime. The next number to check would be 2^(2^127 - 1) - 1, but that's SO LARGE that a 128bit computer would be neccessary to hold it in memory, we can solve this problem by simply using a big hard disk drive as auxiliary memory, but even the optimized Lucas-Lehmer primality test would take MILLENNIA to give an answer (I'm not exaggerating)
3×7×37=777
I discovered that when I was in elementary school and it is still to this day one of my favorite numbers.
Fun Fact about 37 AND 27
1÷27= 0.0370370370370370370370...
1÷37=0.0270270270270270270270...
0:45 Not just the largest known, but the largest (in base 10)
as a kid i thought the job of mathematicians was to come up with cool numbers
Hi sir, really amazing video. Make much more on numbers.👏🙏👍
Another very interesting no is 2022 which is this yr.
1) It's digital root 6 is a "perfect number"(a no whose sum of digits= sum of its all divisors)
2) 2022= 1²+2²+9²+44²
3) It's a very special no as 2+0+2+2=6. According to vortex mathematics 6 is an another lvl no with very special meaning.
4) In this property I use some arrangements of the digits of 2022. 2²+6²+22²+262² = 2×6×22×262 = 69168 (so 69168 also a special no whr the sum of square of 4 nos=product of that nos)
5) 2022= 2¹+2²+2⁵+2⁶+2⁷+2⁸+2⁹+2¹⁰
6) This yr starts & ends on Saturdays.
2022 isn't a perfect number but it's close
@@locomotivetrainstation6053 Thnx for correction... I know that it's not a perfect no but it's digital root is... I actually made a mistake
2:30: 35+34=69
I JUST LOVE YOUR VIDEOS, they always blow up my mind. And btw I have already subbed to your channel :)
You're the best!
I never thought I’d be watching a math video,but here I am
This is the best video I have ever seen.
I'm very glad you enjoyed it!
my favorite number is 1/81 (try it you’ll understand)
0.012345678901234567890....
U mean 0.012345679?
@@thetesseract-wd2sw yes but the 9 should be replaced with an 8 and would be repeating forever (0.0123456789012345678...)
It skips 8 for the same reason 1/9801 skips 98 and 1/998001 skips 998
Seems a final slide of equations was lost but mentioned in voice over .
I like your funny words maths man!
2:59 Isn't this also equal to repeating numbers of 1/7
I actually noticed this for the first time when I was multiplying it with 22, good times
Logan paul's favorite number...
Kaprekar's constant doesn't work with any number that starts with the greatest digit already (e.g. 4321-4123=198)
Any number greater than 1 can be expressed as 1001001 with a different base
4:19 'rectangular pentagon'
3:32 wouldn't that. Be zero
No????
good one!!!! really impressed!!! numbers are amazing......🧠❤
5040 Is an interesting number it's the largest factorial that is also a highly composite number +it's the sum of 42 cosecutive primes (23+...+229)
It's also the sum of the first 100 natural numbers minus the square root of 100
0:25 you can hear the happines in his voice
2:46
Q: Why does 142857 x 7 = 999999?
A: This is a special number unlike other special numbers. Because that number shows up repeatedly in the decimals of 1 ÷ 7
This is the best video ever about fantastic numbers
I'm glad you liked it! :)
0:01 Wait... You like primes?
So you like primes? *Name every prime*
That's my name lol
998,001 also happens to be 999*999
Correct. So 1/998001 = 1/999². Then note that 1/999 = .001001001... = 1/10³ + 1/10⁶ + 1/10⁹ + 1/10¹² + ... and rewrite 1/998001 as (1/10³ + 1/10⁶ + 1/10⁹ + 1/10¹² + ...)². Expand this and you get 1/10⁶ + 2/10⁹ + 3/10¹² + 4/10¹⁵ + ... which explains the pattern in the decimal expansion of 1/998001. As for why the 998 disappears, it's due to the carryover at 999, which turns the 998 into 999. (You want to see all the numbers from 1 to 999999 except for 999998 show up in order in a decimal expansion? Easy, just expand 1/999999².)
Never heard about it on math lessons
Most of these are just random coincidences that are dependent on our base 10 numeric system and our scientific standards (e.g. 360° being a whole circle). Also phi comes up because it's the ratio of one the diagonals and one side of an regular pentagon. You can show this using Ptolemy's theorem. Numberphile has a video on this.
If you take any number and multiply it by nine, and you add up the digits over and over again, they will eventually go back to nine
@@acanadianfry2539 31-40 is 36?
@@acanadianfry2539 Nope, works with any number. Try it!
@@brare45996 11 x 9 = 99
99 doesnt equal 9
@@acanadianfry2539 he said to add the digits
9 + 9 is 18
1 + 8 = 9
@@Minish4rk360 ah i see. my bad then
Mine is 69 👀
indeed, 69=6×9+6+9
♋
1729 can also be expressed as 91 x 19, 91 being the mirror of 19.
wonderful numbers ❤
This video is going to be a hit, I can tell.
5:26 There are now 112 cards in an Uno deck - the customizable wild cards are a thing.
my new equation, courtesy of your video:
i hate numbers + i love this channel and it’s content = i love numbers
thanks for this!
73=1001001 base 2. But if we successively consume rightmost binary zeros, 100101 = 37, 10011 = 19, 1011 = 11 and 111 = 7. If we now consume the 1's: 11 = 3 and finally 1.
10& is my favorite number now, and don’t ask why my eight is in that way, they just woke up one day like that and ig I have to live with it now
I used to (kinda still do) think that all professional mathematicians do all day is calculate around until they find fun facts like these
2:25 I could hear sheldons voice in my head... I promise I'm not crazy
I was looking for that comment
12 is my favorite number. Its the total of bones in each of your fingers, thus in old languages like Biblical Hebrew, its considered an equal number like how 10 is in modern English.
0:50 495 is special its because the infinite loop of the an 3 digit number when picked any number to biggest to smallest minus smal,est to biggest
Interesting video.... But the way you said ramanujan is hilarious