722

722 = 2 x 19 x 19.

722 has a representation as a sum of two squares: 722 = 19² + 19².

722 is the sum of the fourth powers of the first three primes (A133531): 722 = 2⁴ + 3⁴ + 5⁴.

722 is the sum of two distinct factorials, the sum of the factorials of the digits of 26 (A061602): 722 = 2! + 6!

722 is the maximum number of regions into which the plane can be divided by 10 (concave) quadrilaterals (A077591).

Source: What's Special About This Number?