664039728 has 80 divisors (see below), whose sum is σ = 2079331200. Its totient is φ = 201222720.

The previous prime is 664039711. The next prime is 664039729. The reversal of 664039728 is 827930466.

It is not an unprimeable number, because it can be changed into a prime (664039729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65118 + ... + 74621.

It is an arithmetic number, because the mean of its divisors is an integer number (25991640).

Almost surely, 2^664039728 is an apocalyptic number.

It is an amenable number.

664039728 is an abundant number, since it is smaller than the sum of its proper divisors (1415291472).

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

664039728 is a wasteful number, since it uses less digits than its factorization.

664039728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139767 (or 139755 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The square root of 664039728 is about 25768.9683146221. The cubic root of 664039728 is about 872.4315331753.

The spelling of 664039728 in words is "six hundred sixty-four million, thirty-nine thousand, seven hundred twenty-eight".