664406672 has 20 divisors (see below), whose sum is σ = 1287772860. Its totient is φ = 332078208.

The previous prime is 664406657. The next prime is 664406689. The reversal of 664406672 is 276604466.

It can be written as a sum of positive squares in 2 ways, for example, as 520022416 + 144384256 = 22804^2 + 12016^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48098 + ... + 60350.

It is an arithmetic number, because the mean of its divisors is an integer number (64388643).

Almost surely, 2^664406672 is an apocalyptic number.

It is an amenable number.

664406672 is a deficient number, since it is larger than the sum of its proper divisors (623366188).

664406672 is a wasteful number, since it uses less digits than its factorization.

664406672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15650 (or 15644 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 41.

The square root of 664406672 is about 25776.0872127637. The cubic root of 664406672 is about 872.5922035655.

The spelling of 664406672 in words is "six hundred sixty-four million, four hundred six thousand, six hundred seventy-two".