664406564 has 6 divisors (see below), whose sum is σ = 1162711494. Its totient is φ = 332203280.

The previous prime is 664406551. The next prime is 664406579. The reversal of 664406564 is 465604466.

It can be written as a sum of positive squares in only one way, i.e., 510398464 + 154008100 = 22592^2 + 12410^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83050817 + ... + 83050824.

It is an arithmetic number, because the mean of its divisors is an integer number (193785249).

Almost surely, 2^664406564 is an apocalyptic number.

It is an amenable number.

664406564 is a deficient number, since it is larger than the sum of its proper divisors (498304930).

664406564 is a wasteful number, since it uses less digits than its factorization.

664406564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166101645 (or 166101643 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 41.

The square root of 664406564 is about 25776.0851177986. The cubic root of 664406564 is about 872.5921562852.

The spelling of 664406564 in words is "six hundred sixty-four million, four hundred six thousand, five hundred sixty-four".