64640972 has 24 divisors (see below), whose sum is σ = 124507152. Its totient is φ = 29120000.

The previous prime is 64640963. The next prime is 64640993. The reversal of 64640972 is 27904646.

It is a super-2 number, since 2×64640972² = 8356910522209568, which contains 22 as substring.

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, 1529 + ... + 11472.

It is an arithmetic number, because the mean of its divisors is an integer number (5187798).

Almost surely, 2^64640972 is an apocalyptic number.

It is an amenable number.

64640972 is a deficient number, since it is larger than the sum of its proper divisors (59866180).

64640972 is a wasteful number, since it uses less digits than its factorization.

64640972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13129 (or 13127 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 64640972 is about 8039.9609451788. The cubic root of 64640972 is about 401.3309250183.

The spelling of 64640972 in words is "sixty-four million, six hundred forty thousand, nine hundred seventy-two".