640565560 has 32 divisors (see below), whose sum is σ = 1462790160. Its totient is φ = 252400896.

The previous prime is 640565551. The next prime is 640565573. The reversal of 640565560 is 65565046.

It is a super-2 number, since 2×640565560² = 820648473316227200, which contains 22 as substring.

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, 116829 + ... + 122188.

Almost surely, 2^640565560 is an apocalyptic number.

It is an amenable number.

640565560 is an abundant number, since it is smaller than the sum of its proper divisors (822224600).

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

640565560 is a wasteful number, since it uses less digits than its factorization.

640565560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239095 (or 239091 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 37.

The square root of 640565560 is about 25309.3966739628. The cubic root of 640565560 is about 862.0276475432.

The spelling of 640565560 in words is "six hundred forty million, five hundred sixty-five thousand, five hundred sixty".