6

is the integer between and.

Math features

 * 6 is the first perfect number.
 * 6 is the only multiple of 6 to be not an abundant number, since every multiple of a perfect number is abundant, except itself.
 * 6 is an even number.
 * 6 is a triangular number, pronic number and a hexagonal number.
 * 6 is a palindromic number.
 * 6 is the first composite number which is not a square number.