656540660 has 12 divisors (see below), whose sum is σ = 1378735428. Its totient is φ = 262616256.

The previous prime is 656540653. The next prime is 656540669. The reversal of 656540660 is 66045656.

It can be written as a sum of positive squares in 2 ways, for example, as 292341604 + 364199056 = 17098^2 + 19084^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656540669) 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, 16413497 + ... + 16413536.

It is an arithmetic number, because the mean of its divisors is an integer number (114894619).

Almost surely, 2^656540660 is an apocalyptic number.

It is an amenable number.

656540660 is an abundant number, since it is smaller than the sum of its proper divisors (722194768).

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

656540660 is a wasteful number, since it uses less digits than its factorization.

656540660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32827042 (or 32827040 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 38.

The square root of 656540660 is about 25623.0493891730. The cubic root of 656540660 is about 869.1349396696.

The spelling of 656540660 in words is "six hundred fifty-six million, five hundred forty thousand, six hundred sixty".