636604718864 has 10 divisors (see below), whose sum is σ = 1233421642830. Its totient is φ = 318302359424.

The previous prime is 636604718857. The next prime is 636604718887. The reversal of 636604718864 is 468817406636.

It can be written as a sum of positive squares in only one way, i.e., 470623440400 + 165981278464 = 686020^2 + 407408^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19893897449 + ... + 19893897480.

It is an arithmetic number, because the mean of its divisors is an integer number (123342164283).

Almost surely, 2^636604718864 is an apocalyptic number.

It is an amenable number.

636604718864 is a deficient number, since it is larger than the sum of its proper divisors (596816923966).

636604718864 is a wasteful number, since it uses less digits than its factorization.

636604718864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39787794937 (or 39787794931 counting only the distinct ones).

The product of its (nonzero) digits is 27869184, while the sum is 59.

The spelling of 636604718864 in words is "six hundred thirty-six billion, six hundred four million, seven hundred eighteen thousand, eight hundred sixty-four".