638969512 has 32 divisors (see below), whose sum is σ = 1233285120. Its totient is φ = 310201920.

The previous prime is 638969503. The next prime is 638969533. The reversal of 638969512 is 215969836.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41062 + ... + 54442.

It is an arithmetic number, because the mean of its divisors is an integer number (38540160).

Almost surely, 2^638969512 is an apocalyptic number.

It is an amenable number.

638969512 is a deficient number, since it is larger than the sum of its proper divisors (594315608).

638969512 is a wasteful number, since it uses less digits than its factorization.

638969512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13561 (or 13557 counting only the distinct ones).

The product of its digits is 699840, while the sum is 49.

The square root of 638969512 is about 25277.8462690159. The cubic root of 638969512 is about 861.3111027362.

The spelling of 638969512 in words is "six hundred thirty-eight million, nine hundred sixty-nine thousand, five hundred twelve".