638685568076 has 12 divisors (see below), whose sum is σ = 1131847842720. Its totient is φ = 315300470160.

The previous prime is 638685568009. The next prime is 638685568109. The reversal of 638685568076 is 670865586836.

It is a junction number, because it is equal to n+sod(n) for n = 638685567997 and 638685568015.

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, 1010578115 + ... + 1010578746.

It is an arithmetic number, because the mean of its divisors is an integer number (94320653560).

Almost surely, 2^638685568076 is an apocalyptic number.

It is an amenable number.

638685568076 is a deficient number, since it is larger than the sum of its proper divisors (493162274644).

638685568076 is a wasteful number, since it uses less digits than its factorization.

638685568076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2021156944 (or 2021156942 counting only the distinct ones).

The product of its (nonzero) digits is 348364800, while the sum is 68.

The spelling of 638685568076 in words is "six hundred thirty-eight billion, six hundred eighty-five million, five hundred sixty-eight thousand, seventy-six".