640682860 has 12 divisors (see below), whose sum is σ = 1345434048. Its totient is φ = 256273136.

The previous prime is 640682857. The next prime is 640682899. The reversal of 640682860 is 68286046.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16017052 + ... + 16017091.

It is an arithmetic number, because the mean of its divisors is an integer number (112119504).

Almost surely, 2^640682860 is an apocalyptic number.

It is an amenable number.

640682860 is an abundant number, since it is smaller than the sum of its proper divisors (704751188).

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

640682860 is a wasteful number, since it uses less digits than its factorization.

640682860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32034152 (or 32034150 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 640682860 is about 25311.7138890277. The cubic root of 640682860 is about 862.0802623355.

The spelling of 640682860 in words is "six hundred forty million, six hundred eighty-two thousand, eight hundred sixty".