664564131 has 24 divisors (see below), whose sum is σ = 1196792064. Its totient is φ = 345227760.

The previous prime is 664564129. The next prime is 664564133. The reversal of 664564131 is 131465466.

It is a happy number.

664564131 is a `hidden beast` number, since 6 + 6 + 4 + 5 + 641 + 3 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (664564129) and next prime (664564133).

It is not a de Polignac number, because 664564131 - 2¹ = 664564129 is a prime.

It is a super-2 number, since 2×664564131² = 883290968423570322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664564133) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 478791 + ... + 480176.

It is an arithmetic number, because the mean of its divisors is an integer number (49866336).

Almost surely, 2^664564131 is an apocalyptic number.

664564131 is a deficient number, since it is larger than the sum of its proper divisors (532227933).

664564131 is a wasteful number, since it uses less digits than its factorization.

664564131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 958991 (or 958988 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 664564131 is about 25779.1413937703. The cubic root of 664564131 is about 872.6611305490.

The spelling of 664564131 in words is "six hundred sixty-four million, five hundred sixty-four thousand, one hundred thirty-one".