64659664 has 10 divisors (see below), whose sum is σ = 125278130. Its totient is φ = 32329824.

The previous prime is 64659631. The next prime is 64659671. The reversal of 64659664 is 46695646.

It can be written as a sum of positive squares in only one way, i.e., 58369600 + 6290064 = 7640^2 + 2508^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2020599 + ... + 2020630.

It is an arithmetic number, because the mean of its divisors is an integer number (12527813).

Almost surely, 2^64659664 is an apocalyptic number.

It is an amenable number.

64659664 is a deficient number, since it is larger than the sum of its proper divisors (60618466).

64659664 is a wasteful number, since it uses less digits than its factorization.

64659664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4041237 (or 4041231 counting only the distinct ones).

The product of its digits is 933120, while the sum is 46.

The square root of 64659664 is about 8041.1233046136. The cubic root of 64659664 is about 401.3696051023.

It can be divided in two parts, 6465 and 9664, that added together give a square (16129 = 127²).

The spelling of 64659664 in words is "sixty-four million, six hundred fifty-nine thousand, six hundred sixty-four".