664364657 has 10 divisors (see below), whose sum is σ = 730812690. Its totient is φ = 603954560.

The previous prime is 664364651. The next prime is 664364669. The reversal of 664364657 is 756463466.

It can be written as a sum of positive squares in only one way, i.e., 579798241 + 84566416 = 24079^2 + 9196^2 .

It is not a de Polignac number, because 664364657 - 2⁸ = 664364401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664364651) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8048 + ... + 37329.

It is an arithmetic number, because the mean of its divisors is an integer number (73081269).

Almost surely, 2^664364657 is an apocalyptic number.

It is an amenable number.

664364657 is a deficient number, since it is larger than the sum of its proper divisors (66448033).

664364657 is an frugal number, since it uses more digits than its factorization.

664364657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45421 (or 45388 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 47.

The square root of 664364657 is about 25775.2722003086. The cubic root of 664364657 is about 872.5738098438.

The spelling of 664364657 in words is "six hundred sixty-four million, three hundred sixty-four thousand, six hundred fifty-seven".