638617748672 has 14 divisors (see below), whose sum is σ = 1267257095148. Its totient is φ = 319308874304.

The previous prime is 638617748641. The next prime is 638617748711. The reversal of 638617748672 is 276847716836.

It is a junction number, because it is equal to n+sod(n) for n = 638617748599 and 638617748608.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4989201098 + ... + 4989201225.

Almost surely, 2^638617748672 is an apocalyptic number.

It is an amenable number.

638617748672 is a deficient number, since it is larger than the sum of its proper divisors (628639346476).

638617748672 is an equidigital number, since it uses as much as digits as its factorization.

638617748672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9978402335 (or 9978402325 counting only the distinct ones).

The product of its digits is 113799168, while the sum is 65.

The spelling of 638617748672 in words is "six hundred thirty-eight billion, six hundred seventeen million, seven hundred forty-eight thousand, six hundred seventy-two".