901

901 = 17 x 53.

901 has two representations as a sum of two squares: 901 = 1² + 30² = 15² + 26².

901 is the hypotenuse of two primitive Pythagorean triples: 901² = 60² + 899² = 451² + 780².

901 is a centered triangular number.

901 is the sum of the digits of the first 100 positive integers.

901 is a telephone area code in the state of Tennessee.

Source: Number Gossip