64139968 has 28 divisors (see below), whose sum is σ = 128139952. Its totient is φ = 31852800.

The previous prime is 64139951. The next prime is 64139987. The reversal of 64139968 is 86993146.

It is a super-2 number, since 2×64139968² = 8227870990082048, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6346 + ... + 12982.

Almost surely, 2^64139968 is an apocalyptic number.

It is an amenable number.

64139968 is a deficient number, since it is larger than the sum of its proper divisors (63999984).

64139968 is a wasteful number, since it uses less digits than its factorization.

64139968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6800 (or 6790 counting only the distinct ones).

The product of its digits is 279936, while the sum is 46.

The square root of 64139968 is about 8008.7432222540. The cubic root of 64139968 is about 400.2913876815.

The spelling of 64139968 in words is "sixty-four million, one hundred thirty-nine thousand, nine hundred sixty-eight".