638877064 has 32 divisors (see below), whose sum is σ = 1371038400. Its totient is φ = 273401280.

The previous prime is 638877059. The next prime is 638877067. The reversal of 638877064 is 460778836.

It is a junction number, because it is equal to n+sod(n) for n = 638876999 and 638877017.

It is not an unprimeable number, because it can be changed into a prime (638877067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31659 + ... + 47749.

It is an arithmetic number, because the mean of its divisors is an integer number (42844950).

Almost surely, 2^638877064 is an apocalyptic number.

It is an amenable number.

638877064 is an abundant number, since it is smaller than the sum of its proper divisors (732161336).

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

638877064 is a wasteful number, since it uses less digits than its factorization.

638877064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16813 (or 16809 counting only the distinct ones).

The product of its (nonzero) digits is 1354752, while the sum is 49.

The square root of 638877064 is about 25276.0175660645. The cubic root of 638877064 is about 861.2695617196.

The spelling of 638877064 in words is "six hundred thirty-eight million, eight hundred seventy-seven thousand, sixty-four".