665728056 has 48 divisors (see below), whose sum is σ = 2060588400. Its totient is φ = 190207872.

The previous prime is 665728039. The next prime is 665728081. The reversal of 665728056 is 650827566.

665728056 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 659941 + ... + 660948.

It is an arithmetic number, because the mean of its divisors is an integer number (42928925).

Almost surely, 2^665728056 is an apocalyptic number.

It is an amenable number.

665728056 is an abundant number, since it is smaller than the sum of its proper divisors (1394860344).

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

665728056 is a wasteful number, since it uses less digits than its factorization.

665728056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1320908 (or 1320901 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The square root of 665728056 is about 25801.7064551940. The cubic root of 665728056 is about 873.1702962106.

The spelling of 665728056 in words is "six hundred sixty-five million, seven hundred twenty-eight thousand, fifty-six".