640502404668 has 96 divisors (see below), whose sum is σ = 1904788408320. Its totient is φ = 182325349440.

The previous prime is 640502404627. The next prime is 640502404673. The reversal of 640502404668 is 866404205046.

640502404668 is a `hidden beast` number, since 6 + 4 + 0 + 502 + 40 + 46 + 68 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1358271 + ... + 1768022.

It is an arithmetic number, because the mean of its divisors is an integer number (19841545920).

Almost surely, 2^640502404668 is an apocalyptic number.

It is an amenable number.

640502404668 is an abundant number, since it is smaller than the sum of its proper divisors (1264286003652).

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

640502404668 is a wasteful number, since it uses less digits than its factorization.

640502404668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3126584 (or 3126576 counting only the distinct ones).

The product of its (nonzero) digits is 1105920, while the sum is 45.

The spelling of 640502404668 in words is "six hundred forty billion, five hundred two million, four hundred four thousand, six hundred sixty-eight".