This discussion board is a place to discuss our Daily Challenges and the math and science
related to those challenges. Explanations are more than just a solution — they should
explain the steps and thinking strategies that you used to obtain the solution. Comments
should further the discussion of math and science.

When posting on Brilliant:

Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .

Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.

Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.

Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.

Markdown

Appears as

*italics* or _italics_

italics

**bold** or __bold__

bold

- bulleted - list

bulleted

list

1. numbered 2. list

numbered

list

Note: you must add a full line of space before and after lists for them to show up correctly

24 because it is 4!, (2^1)(3^2)(1^3), it is an antiprime, also because of challenge 24, 24 hours in a day, 2+2=4, 2*2=4, 2^2=4, 2^(24-1)=8388608 which is a pretty cool power of 2 since it contains a lot of 8's, and 5^2-1^2, 7^2-5^2.

Don't laugh, I think my favorite number is 64. My life is full of coincidences related with that number, starting with my birthday year. 6+4=10 is the base of our decimal system, 64 is the 6th power of 2, 6 is the first perfect number and 4 is also a power of 2, 6-4=2, my favorite numerical base, 6*4=24, the number of hours of our day, so, overall, it has a lot of other of my favorite numbers. These is not over the top properties but it is enough to me.

@Mary Brown
–
Read the "The Hitchhiker's Guide to the Galaxy" book and you will understand everything. Sometimes it is a litte bit confusion, but it is still a essential book for people who do something with math (why? I don't know).

In other words 42 is a random number, which a random guy wrote in a random book, and it is the answer of life, universe and everything, and that's why it is so special.

@CodeCrafter 1
–
Actually I loved the bits of The Hitchhiker's Guide to the Galaxy, that I heard once on the radio. Forgot about 42 being the answer to everything. Must read it properly. Thanks.

@CodeCrafter 1
–
42 is not a simple random number. There are a number of properties for which, it is the first or the last know number having them. And at least for one:

"42 is the only known value that is the number of sets of four distinct positive integers a, b, c, d, each less than the value itself, such that ab − cd, ac − bd, and ad − bc are each multiples of the value. Whether there are other values remains an open question."

My favorite number is $4679307774$. It has $10$ digits, and it you sum each digit raised to the $10$th power (e.g. $4^{10}+6^{10}+7^{10}+9^{10}+3^{10}+0^{10}+7^{10}+7^{10}+7^{10}+4^{10}$), you will get $4679307774$, the same number.

I mean it surprises me that we do not have its closed form!!! And this is the kind of number which can be EASILY explained to anyone using its definition, but yet, no one would know the vast amount of properties it has.....!!

Easy Math Editor

This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.

When posting on Brilliant:

`*italics*`

or`_italics_`

italics`**bold**`

or`__bold__`

boldNote: you must add a full line of space before and after lists for them to show up correctlyparagraph 1

paragraph 2

`[example link](https://brilliant.org)`

`> This is a quote`

Remember to wrap math in`\(`

...`\)`

or`\[`

...`\]`

to ensure proper formatting.`2 \times 3`

`2^{34}`

`a_{i-1}`

`\frac{2}{3}`

`\sqrt{2}`

`\sum_{i=1}^3`

`\sin \theta`

`\boxed{123}`

## Comments

Sort by:

TopNewest24 because it is 4!, (2^1)

(3^2)(1^3), it is an antiprime, also because of challenge 24, 24 hours in a day, 2+2=4, 2*2=4, 2^2=4, 2^(24-1)=8388608 which is a pretty cool power of 2 since it contains a lot of 8's, and 5^2-1^2, 7^2-5^2.Log in to reply

Pretty interesting!

Log in to reply

Don't laugh, I think my favorite number is 64. My life is full of coincidences related with that number, starting with my birthday year. 6+4=10 is the base of our decimal system, 64 is the 6th power of 2, 6 is the first perfect number and 4 is also a power of 2, 6-4=2, my favorite numerical base, 6*4=24, the number of hours of our day, so, overall, it has a lot of other of my favorite numbers. These is not over the top properties but it is enough to me.

Log in to reply

I never saw 64 that way.

Log in to reply

73 and 42.

73 is the 21th prime number

$21 = 7 * 3$

37 is the 12th prime number(Do you see the symmetry).

73 is in base 2 1001001 which is symmetric.

42 is coolest of each number(hopefully you know why, if you don't know why,

don't panic).Log in to reply

Reference from big bang theory? :)

Log in to reply

Yes ;)

Log in to reply

Nice symmetry. And yes, 42 is the supreme number. Don't forget your towel!

Log in to reply

42 is so fly, I accidentally missed the ground

Log in to reply

Log in to reply

In other words 42 is a random number, which a random guy wrote in a random book, and it is the answer of life, universe and everything, and that's why it is so special.

Log in to reply

Log in to reply

"42 is the only known value that is the number of sets of four distinct positive integers a, b, c, d, each less than the value itself, such that ab − cd, ac − bd, and ad − bc are each multiples of the value. Whether there are other values remains an open question."

Quoted from the Wikipedia.

Log in to reply

Log in to reply

13, because no one like it

Log in to reply

Strange reason ;-)

Log in to reply

lol reverse psychology

Log in to reply

My favorite number is $4679307774$. It has $10$ digits, and it you sum each digit raised to the $10$th power (e.g. $4^{10}+6^{10}+7^{10}+9^{10}+3^{10}+0^{10}+7^{10}+7^{10}+7^{10}+4^{10}$), you will get $4679307774$, the same number.

Log in to reply

Does such a number exists in every base ? So in base n a n-digit number with is the same as raise the digits to n and add up these numbers.

Log in to reply

this page has numbers for different bases

Log in to reply

Log in to reply

That is a really interesting question, to which I have no answer. I would definitely love to look into this more, though.

Log in to reply

Interesting!!

Log in to reply

Are there any other numbers with similar property?

Log in to reply

oeis page.

Yes. View thisLog in to reply

Well, my favourite number, even though is kind of cliche, is the Euler Mascheroni Constant!!

I mean it surprises me that we do not have its closed form!!! And this is the kind of number which can be EASILY explained to anyone using its definition, but yet, no one would know the vast amount of properties it has.....!!

Log in to reply

You forgot, it should have be a natural number. I'm not taking it down, I'm sure it must be a very sexy number.

Log in to reply

Curious number indeed!

Log in to reply

My favourite number is $142857$

It is a cyclic number

It is a kaprekar number

It is a harshad number

$\frac{1}{7}=0.\overline{142857}$ and interestingly, $\frac{1}{142857}=0.\overline{000007}$

$142+857=999$ and $14+28+57=99$

Log in to reply