640207181604 has 24 divisors (see below), whose sum is σ = 1499329003648. Its totient is φ = 212614930080.

The previous prime is 640207181597. The next prime is 640207181629. The reversal of 640207181604 is 406181702046.

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, 98429587 + ... + 98436090.

Almost surely, 2^640207181604 is an apocalyptic number.

It is an amenable number.

640207181604 is an abundant number, since it is smaller than the sum of its proper divisors (859121822044).

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

640207181604 is a wasteful number, since it uses less digits than its factorization.

640207181604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196865955 (or 196865953 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

The spelling of 640207181604 in words is "six hundred forty billion, two hundred seven million, one hundred eighty-one thousand, six hundred four".