Favorite numbers

Belphegor’s prime

$1000000000000066600000000000001$

Or in other words, 1, followed by 13 zeroes, followed by 666, followed by 13 more zeroes, then another 1. Too spoopy!!

Zero

Come on, you know this one.

On

Combinatorial game theory says hi!

Combinatorial game theory also says that $\text{on}=\{\text{on}|\}$ isn’t actually a number, but we like to have fun here.

$\text{off}$ is cool too.

$\sqrt{2}$

I just think it’s neat.

$2$

I’ve recently come to appreciate 2 for the super cool number it is. Go check the Fun Facts page for a really cool property about powers of 2.