638910996498 has 48 divisors (see below), whose sum is σ = 1465806452760. Its totient is φ = 200433166848.

The previous prime is 638910996487. The next prime is 638910996587. The reversal of 638910996498 is 894699019836.

638910996498 is a `hidden beast` number, since 6 + 38 + 9 + 10 + 9 + 96 + 498 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 447043343769 + 191867652729 = 668613^2 + 438027^2 .

It is a super-2 number, since 2×638910996498² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9301536 + ... + 9369972.

Almost surely, 2^638910996498 is an apocalyptic number.

638910996498 is an abundant number, since it is smaller than the sum of its proper divisors (826895456262).

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

638910996498 is a wasteful number, since it uses less digits than its factorization.

638910996498 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98971 (or 98968 counting only the distinct ones).

The product of its (nonzero) digits is 181398528, while the sum is 72.

The spelling of 638910996498 in words is "six hundred thirty-eight billion, nine hundred ten million, nine hundred ninety-six thousand, four hundred ninety-eight".