664522728 has 16 divisors (see below), whose sum is σ = 1661306880. Its totient is φ = 221507568.

The previous prime is 664522717. The next prime is 664522759. The reversal of 664522728 is 827225466.

It is a self number, because there is not a number n which added to its sum of digits gives 664522728.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13844200 + ... + 13844247.

It is an arithmetic number, because the mean of its divisors is an integer number (103831680).

Almost surely, 2^664522728 is an apocalyptic number.

It is an amenable number.

664522728 is an abundant number, since it is smaller than the sum of its proper divisors (996784152).

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

664522728 is a wasteful number, since it uses less digits than its factorization.

664522728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27688456 (or 27688452 counting only the distinct ones).

The product of its digits is 322560, while the sum is 42.

The square root of 664522728 is about 25778.3383483110. The cubic root of 664522728 is about 872.6430076233.

The spelling of 664522728 in words is "six hundred sixty-four million, five hundred twenty-two thousand, seven hundred twenty-eight".