657809664 has 72 divisors (see below), whose sum is σ = 1761208512. Its totient is φ = 217958400.

The previous prime is 657809653. The next prime is 657809693. The reversal of 657809664 is 466908756.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130389 + ... + 135339.

Almost surely, 2^657809664 is an apocalyptic number.

657809664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 657809664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (880604256).

657809664 is an abundant number, since it is smaller than the sum of its proper divisors (1103398848).

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

657809664 is a wasteful number, since it uses less digits than its factorization.

657809664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5143 (or 5129 counting only the distinct ones).

The product of its (nonzero) digits is 2177280, while the sum is 51.

The square root of 657809664 is about 25647.8003735213. The cubic root of 657809664 is about 869.6945525699.

The spelling of 657809664 in words is "six hundred fifty-seven million, eight hundred nine thousand, six hundred sixty-four".