638407754776 has 16 divisors (see below), whose sum is σ = 1305834044040. Its totient is φ = 290185343040.

The previous prime is 638407754767. The next prime is 638407754779. The reversal of 638407754776 is 677457704836.

It is a super-2 number, since 2×638407754776² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638407754779) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3627316701 + ... + 3627316876.

Almost surely, 2^638407754776 is an apocalyptic number.

It is an amenable number.

638407754776 is an abundant number, since it is smaller than the sum of its proper divisors (667426289264).

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

638407754776 is a wasteful number, since it uses less digits than its factorization.

638407754776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7254633594 (or 7254633590 counting only the distinct ones).

The product of its (nonzero) digits is 165957120, while the sum is 64.

The spelling of 638407754776 in words is "six hundred thirty-eight billion, four hundred seven million, seven hundred fifty-four thousand, seven hundred seventy-six".