638840568996 has 72 divisors (see below), whose sum is σ = 1856207406144. Its totient is φ = 181470801600.

The previous prime is 638840568991. The next prime is 638840569007. The reversal of 638840568996 is 699865048836.

638840568996 is a `hidden beast` number, since 63 + 88 + 405 + 6 + 89 + 9 + 6 = 666.

It is not an unprimeable number, because it can be changed into a prime (638840568991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7283230 + ... + 7370421.

Almost surely, 2^638840568996 is an apocalyptic number.

It is an amenable number.

638840568996 is an abundant number, since it is smaller than the sum of its proper divisors (1217366837148).

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

638840568996 is a wasteful number, since it uses less digits than its factorization.

638840568996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14653841 (or 14653836 counting only the distinct ones).

The product of its (nonzero) digits is 537477120, while the sum is 72.

The spelling of 638840568996 in words is "six hundred thirty-eight billion, eight hundred forty million, five hundred sixty-eight thousand, nine hundred ninety-six".