664664737 has 6 divisors (see below), whose sum is σ = 730582034. Its totient is φ = 604240560.

The previous prime is 664664731. The next prime is 664664771. The reversal of 664664737 is 737466466.

It can be written as a sum of positive squares in only one way, i.e., 657460881 + 7203856 = 25641^2 + 2684^2 .

It is a de Polignac number, because none of the positive numbers 2^k-664664737 is a prime.

It is a super-2 number, since 2×664664737² = 883558425222558338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664664731) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2746428 + ... + 2746669.

Almost surely, 2^664664737 is an apocalyptic number.

It is an amenable number.

664664737 is a deficient number, since it is larger than the sum of its proper divisors (65917297).

664664737 is a wasteful number, since it uses less digits than its factorization.

664664737 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5493119 (or 5493108 counting only the distinct ones).

The product of its digits is 3048192, while the sum is 49.

The square root of 664664737 is about 25781.0926261863. The cubic root of 664664737 is about 872.7051646819.

The spelling of 664664737 in words is "six hundred sixty-four million, six hundred sixty-four thousand, seven hundred thirty-seven".