638607936168 has 64 divisors (see below), whose sum is σ = 1783198540800. Its totient is φ = 211754799360.

The previous prime is 638607936167. The next prime is 638607936203. The reversal of 638607936168 is 861639706836.

638607936168 is a `hidden beast` number, since 6 + 3 + 8 + 6 + 0 + 7 + 9 + 3 + 616 + 8 = 666.

It is a super-2 number, since 2×638607936168² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638607936167) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7698321 + ... + 7780832.

It is an arithmetic number, because the mean of its divisors is an integer number (27862477200).

Almost surely, 2^638607936168 is an apocalyptic number.

It is an amenable number.

638607936168 is an abundant number, since it is smaller than the sum of its proper divisors (1144590604632).

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

638607936168 is a wasteful number, since it uses less digits than its factorization.

638607936168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15479359 (or 15479349 counting only the distinct ones).

The product of its (nonzero) digits is 47029248, while the sum is 63.

The spelling of 638607936168 in words is "six hundred thirty-eight billion, six hundred seven million, nine hundred thirty-six thousand, one hundred sixty-eight".