663680644 has 27 divisors (see below), whose sum is σ = 1277716503. Its totient is φ = 301415400.

The previous prime is 663680623. The next prime is 663680651. The reversal of 663680644 is 446086366.

The square root of 663680644 is 25762.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 663680644.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 566179 + ... + 567349.

Almost surely, 2^663680644 is an apocalyptic number.

663680644 is the 25762-nd square number.

It is an amenable number.

663680644 is a deficient number, since it is larger than the sum of its proper divisors (614035859).

663680644 is a wasteful number, since it uses less digits than its factorization.

663680644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2368 (or 1184 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 43.

The cubic root of 663680644 is about 872.2742470586.

The spelling of 663680644 in words is "six hundred sixty-three million, six hundred eighty thousand, six hundred forty-four".