640806888 has 32 divisors (see below), whose sum is σ = 1632247200. Its totient is φ = 209571648.

The previous prime is 640806877. The next prime is 640806893. The reversal of 640806888 is 888608046.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

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 7 ways as a sum of consecutive naturals, for example, 250618 + ... + 253161.

It is an arithmetic number, because the mean of its divisors is an integer number (51007725).

Almost surely, 2^640806888 is an apocalyptic number.

It is an amenable number.

640806888 is an abundant number, since it is smaller than the sum of its proper divisors (991440312).

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

640806888 is a wasteful number, since it uses less digits than its factorization.

640806888 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 503841 (or 503837 counting only the distinct ones).

The product of its (nonzero) digits is 589824, while the sum is 48.

The square root of 640806888 is about 25314.1637823571. The cubic root of 640806888 is about 862.1358879804.

The spelling of 640806888 in words is "six hundred forty million, eight hundred six thousand, eight hundred eighty-eight".