665997256 has 16 divisors (see below), whose sum is σ = 1249326540. Its totient is φ = 332843520.

The previous prime is 665997221. The next prime is 665997263. The reversal of 665997256 is 652799566.

665997256 is a nontrivial binomial coefficient, being equal to C(36497, 2).

It can be written as a sum of positive squares in 2 ways, for example, as 553849156 + 112148100 = 23534^2 + 10590^2 .

It is a junction number, because it is equal to n+sod(n) for n = 665997197 and 665997206.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 36496.

Almost surely, 2^665997256 is an apocalyptic number.

665997256 is the 36496-th triangular number.

665997256 is the 12166-th centered nonagonal number.

It is an amenable number.

665997256 is a deficient number, since it is larger than the sum of its proper divisors (583329284).

665997256 is a wasteful number, since it uses less digits than its factorization.

665997256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38784 (or 38780 counting only the distinct ones).

The product of its digits is 6123600, while the sum is 55.

The square root of 665997256 is about 25806.9226371530. The cubic root of 665997256 is about 873.2879747759.

The spelling of 665997256 in words is "six hundred sixty-five million, nine hundred ninety-seven thousand, two hundred fifty-six".