640546664 has 64 divisors (see below), whose sum is σ = 1295222400. Its totient is φ = 296352000.

The previous prime is 640546609. The next prime is 640546721. The reversal of 640546664 is 466645046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 608939 + ... + 609989.

It is an arithmetic number, because the mean of its divisors is an integer number (20237850).

Almost surely, 2^640546664 is an apocalyptic number.

It is an amenable number.

640546664 is an abundant number, since it is smaller than the sum of its proper divisors (654675736).

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

640546664 is a wasteful number, since it uses less digits than its factorization.

640546664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1194 (or 1190 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 41.

The square root of 640546664 is about 25309.0233711220. The cubic root of 640546664 is about 862.0191711615.

The spelling of 640546664 in words is "six hundred forty million, five hundred forty-six thousand, six hundred sixty-four".