# Number Gossip

(Enter a number and I'll tell you everything you wanted to know about it but were afraid to ask.)

## Unique Properties of 65

- 65 is the smallest number that becomes square if its reverse is either added to or subtracted from it
- 65 is the difference of fourth powers of the first two primes 65 = 3
^{4}− 2^{4} - 65 is the only number which gives a prime square, on adding as well as subtracting its reverse from it (65 + 56 = 11
^{2}, 65 − 56 = 3^{2}) - 65 is the smallest composite number of the form n
^{2}+ 1, where n is even - 65 is the magic constant of the 5 by 5 magic square
- 65 is the smallest hypotenuse of two different primitive Pythagorean triangles (33, 56, 65 and 16, 63, 65)
- 65 is the smallest hypotenuse of a primitive Pythagorean triangle whose 3 sides are composite integers
- 65 is the smallest number that is a sum of 2 distinct nonzero squares in more than one way