664929944 has 32 divisors (see below), whose sum is σ = 1451740320. Its totient is φ = 279591936.

The previous prime is 664929907. The next prime is 664929949. The reversal of 664929944 is 449929466.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664929949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 109049 + ... + 114984.

It is an arithmetic number, because the mean of its divisors is an integer number (45366885).

Almost surely, 2^664929944 is an apocalyptic number.

It is an amenable number.

664929944 is an abundant number, since it is smaller than the sum of its proper divisors (786810376).

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

664929944 is a wasteful number, since it uses less digits than its factorization.

664929944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224099 (or 224095 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 53.

The square root of 664929944 is about 25786.2355531008. The cubic root of 664929944 is about 872.8212215596.

The spelling of 664929944 in words is "six hundred sixty-four million, nine hundred twenty-nine thousand, nine hundred forty-four".