660840664 has 32 divisors (see below), whose sum is σ = 1366923600. Its totient is φ = 297003520.

The previous prime is 660840647. The next prime is 660840701. The reversal of 660840664 is 466048066.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34357 + ... + 50020.

Almost surely, 2^660840664 is an apocalyptic number.

It is an amenable number.

660840664 is an abundant number, since it is smaller than the sum of its proper divisors (706082936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

660840664 is a wasteful number, since it uses less digits than its factorization.

660840664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84483 (or 84479 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 40.

The square root of 660840664 is about 25706.8213515401. The cubic root of 660840664 is about 871.0282746433.

The spelling of 660840664 in words is "six hundred sixty million, eight hundred forty thousand, six hundred sixty-four".