664823646 has 32 divisors (see below), whose sum is σ = 1479271680. Its totient is φ = 221325048.

The previous prime is 664823639. The next prime is 664823683. The reversal of 664823646 is 646328466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37215 + ... + 52101.

It is an arithmetic number, because the mean of its divisors is an integer number (46227240).

Almost surely, 2^664823646 is an apocalyptic number.

664823646 is an abundant number, since it is smaller than the sum of its proper divisors (814448034).

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

664823646 is a wasteful number, since it uses less digits than its factorization.

664823646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15725 (or 15719 counting only the distinct ones).

The product of its digits is 995328, while the sum is 45.

The square root of 664823646 is about 25784.1743323303. The cubic root of 664823646 is about 872.7747083414.

The spelling of 664823646 in words is "six hundred sixty-four million, eight hundred twenty-three thousand, six hundred forty-six".