638636536056 has 16 divisors (see below), whose sum is σ = 1596591340200. Its totient is φ = 212878845344.

The previous prime is 638636536049. The next prime is 638636536067. The reversal of 638636536056 is 650635636836.

It is a junction number, because it is equal to n+sod(n) for n = 638636535987 and 638636536005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13304927811 + ... + 13304927858.

Almost surely, 2^638636536056 is an apocalyptic number.

It is an amenable number.

638636536056 is an abundant number, since it is smaller than the sum of its proper divisors (957954804144).

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

638636536056 is a wasteful number, since it uses less digits than its factorization.

638636536056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26609855678 (or 26609855674 counting only the distinct ones).

The product of its (nonzero) digits is 41990400, while the sum is 57.

The spelling of 638636536056 in words is "six hundred thirty-eight billion, six hundred thirty-six million, five hundred thirty-six thousand, fifty-six".