638407075881 has 8 divisors (see below), whose sum is σ = 853946443584. Its totient is φ = 424236212720.

The previous prime is 638407075877. The next prime is 638407075897. The reversal of 638407075881 is 188570704836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 638407075881 - 2² = 638407075877 is a prime.

It is a super-2 number, since 2×638407075881² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638407075981) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342125046 + ... + 342126911.

It is an arithmetic number, because the mean of its divisors is an integer number (106743305448).

Almost surely, 2^638407075881 is an apocalyptic number.

It is an amenable number.

638407075881 is a deficient number, since it is larger than the sum of its proper divisors (215539367703).

638407075881 is a wasteful number, since it uses less digits than its factorization.

638407075881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684252271.

The product of its (nonzero) digits is 9031680, while the sum is 57.

The spelling of 638407075881 in words is "six hundred thirty-eight billion, four hundred seven million, seventy-five thousand, eight hundred eighty-one".