664631586 has 12 divisors (see below), whose sum is σ = 1440035142. Its totient is φ = 221543856.

The previous prime is 664631579. The next prime is 664631593. The reversal of 664631586 is 685136466.

664631586 is a `hidden beast` number, since 6 + 6 + 4 + 63 + 1 + 586 = 666.

It is an interprime number because it is at equal distance from previous prime (664631579) and next prime (664631593).

It can be written as a sum of positive squares in only one way, i.e., 565250625 + 99380961 = 23775^2 + 9969^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 18461971 + ... + 18462006.

Almost surely, 2^664631586 is an apocalyptic number.

664631586 is an abundant number, since it is smaller than the sum of its proper divisors (775403556).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664631586 is a wasteful number, since it uses less digits than its factorization.

664631586 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36923985 (or 36923982 counting only the distinct ones).

The product of its digits is 622080, while the sum is 45.

The square root of 664631586 is about 25780.4496857599. The cubic root of 664631586 is about 872.6906553469.

It can be divided in two parts, 664 and 631586, that added together give a triangular number (632250 = T₁₁₂₄).

The spelling of 664631586 in words is "six hundred sixty-four million, six hundred thirty-one thousand, five hundred eighty-six".