665280656 has 20 divisors (see below), whose sum is σ = 1289910000. Its totient is φ = 332400672.

The previous prime is 665280653. The next prime is 665280673. The reversal of 665280656 is 656082566.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (665280653) 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 3 ways as a sum of consecutive naturals, for example, 9095 + ... + 37593.

It is an arithmetic number, because the mean of its divisors is an integer number (64495500).

Almost surely, 2^665280656 is an apocalyptic number.

It is an amenable number.

665280656 is a deficient number, since it is larger than the sum of its proper divisors (624629344).

665280656 is a wasteful number, since it uses less digits than its factorization.

665280656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29966 (or 29960 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 44.

The square root of 665280656 is about 25793.0350288600. The cubic root of 665280656 is about 872.9746487873.

The spelling of 665280656 in words is "six hundred sixty-five million, two hundred eighty thousand, six hundred fifty-six".