9999 is a Kaprekar Number (a number that when squared and then the digits in the squared number are added together equal the original number)
7928 is a Friedman Number (a positive integer which can be written in some non-trivial way using its own digits, together with the symbols + - x / ^ ( ) and concatenation. For example, 25 = 52 and 126 = 21 * 6.)
2 is the only even prime number.
there is seriously some trippy math stuff in here. I can't believe someone took the time to do this.


