664507656 has 48 divisors (see below), whose sum is σ = 1805210160. Its totient is φ = 220825440.

The previous prime is 664507633. The next prime is 664507699. The reversal of 664507656 is 656705466.

It is a super-2 number, since 2×664507656² = 883140849765228672, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9891 + ... + 37773.

It is an arithmetic number, because the mean of its divisors is an integer number (37608545).

Almost surely, 2^664507656 is an apocalyptic number.

It is an amenable number.

664507656 is an abundant number, since it is smaller than the sum of its proper divisors (1140702504).

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

664507656 is a wasteful number, since it uses less digits than its factorization.

664507656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28226 (or 28219 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 45.

The square root of 664507656 is about 25778.0460081830. The cubic root of 664507656 is about 872.6364101189.

The spelling of 664507656 in words is "six hundred sixty-four million, five hundred seven thousand, six hundred fifty-six".