My favorite number is: $3435$. You may ask: "why?" since this number seems, à priori, pretty boring. But it turns out that it is very interesting: it is the only natural number (along with $1$ ) which have the following property: \begin{aligned}\color{#3D99F6}3\color{#D61F06}4\color{#20A900}35&=\color{#3D99F6}3^{\color{#3D99F6}3}+\color{#D61F06}4^{\color{#D61F06}4}+\color{#20A900}3^{\color{#20A900}3}+5^5\\&= \color{#3D99F6}{27}+\color{#D61F06}{256}+\color{#20A900}{27}+3125\\ &={3435}.\end{aligned} I also like Mills' constant which is the smallest number $\rm A$ such that $\lfloor \rm A^{3^n} \rfloor$ is a prime number for every $n\in\mathbb N$. Its value is approximately equal to $1.306$ and the primes generated by Mills' constant are known as Mills primes; if the Riemann hypothesis is true, the sequence begins: $2, 11, 1361, 2521008887, \ldots$ (sequence A051254 in OEIS). And what about you? What is your favorite number, and why? Leave a comment! ;-)

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$1023$ because...

• In alphanumeric code, it spells my initials
• $2^{10}-1$ looks nice
• Contains digits 0 through 3
• It was especially special on October 23, 2013
• 10:23 is my average bedtime

- 6 years ago

73, from the Big Bang Theory

8... because in a digital clock all the digits and also the letters can be formed by 8.. for example- to form 3 in a digital clock we just have to take out the two sticks on the left...

- 6 years ago

I was born on the fifth hour of the fifth day of the fifth month of the year on the fifth floor of the hospital, and I used to be 5 years old. That's why my favorite number is $145=1!+4!+5!$.

- 6 years ago

1. My family literally revolves around 5 and any number who's ultimate digit sum is 5.

- 6 years ago

4, because I used to think that numbers had personalities. 4 is kind.

- 5 years, 12 months ago