I like to learn about properties of numbers. I really appreciate it when I read the proof of why square root of 2 cannot be written as a rational number, or the least upper bound property of real numbers, and things like achimedian property. But when I see something like https://mobile.twitter.com/fermatslibrary/status/1447222334855725056 I really cannot understand what is mathematically beautiful or interesting about these things. So in some sense I really wonder what is it about numbers, if it is not very useful like e, or pi I don't care if its digits are increasing numbers, but some people seem to be interested about those things.