638718968322 has 30 divisors (see below), whose sum is σ = 1431226407699. Its totient is φ = 212902932060.

The previous prime is 638718968309. The next prime is 638718968411. The reversal of 638718968322 is 223869817836.

It can be written as a sum of positive squares in only one way, i.e., 319359484161 + 319359484161 = 565119^2 + 565119^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=565119.

It is a self number, because there is not a number n which added to its sum of digits gives 638718968322.

It is an unprimeable number.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 10140747 + ... + 10203537.

Almost surely, 2^638718968322 is an apocalyptic number.

638718968322 is an abundant number, since it is smaller than the sum of its proper divisors (792507439377).

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

638718968322 is an frugal number, since it uses more digits than its factorization.

638718968322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125596 (or 62796 counting only the distinct ones).

The product of its digits is 41803776, while the sum is 63.

The spelling of 638718968322 in words is "six hundred thirty-eight billion, seven hundred eighteen million, nine hundred sixty-eight thousand, three hundred twenty-two".