664532447994 has 12 divisors (see below), whose sum is σ = 1439820304026. Its totient is φ = 221510815992.

The previous prime is 664532447933. The next prime is 664532448001. The reversal of 664532447994 is 499744235466.

664532447994 is a `hidden beast` number, since 6 + 6 + 4 + 53 + 24 + 479 + 94 = 666.

It can be written as a sum of positive squares in only one way, i.e., 638840525625 + 25691922369 = 799275^2 + 160287^2 .

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

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, 18459234649 + ... + 18459234684.

Almost surely, 2^664532447994 is an apocalyptic number.

664532447994 is an abundant number, since it is smaller than the sum of its proper divisors (775287856032).

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

664532447994 is a wasteful number, since it uses less digits than its factorization.

664532447994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36918469341 (or 36918469338 counting only the distinct ones).

The product of its digits is 156764160, while the sum is 63.

The spelling of 664532447994 in words is "six hundred sixty-four billion, five hundred thirty-two million, four hundred forty-seven thousand, nine hundred ninety-four".