656478612 has 18 divisors (see below), whose sum is σ = 1659432138. Its totient is φ = 218826192.

The previous prime is 656478611. The next prime is 656478619. The reversal of 656478612 is 216874656.

656478612 is a `hidden beast` number, since 6 + 564 + 7 + 86 + 1 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 463713156 + 192765456 = 21534^2 + 13884^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656478611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9117723 + ... + 9117794.

Almost surely, 2^656478612 is an apocalyptic number.

It is an amenable number.

656478612 is an abundant number, since it is smaller than the sum of its proper divisors (1002953526).

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

656478612 is a wasteful number, since it uses less digits than its factorization.

656478612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18235527 (or 18235522 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 656478612 is about 25621.8385757151. The cubic root of 656478612 is about 869.1075588908.

The spelling of 656478612 in words is "six hundred fifty-six million, four hundred seventy-eight thousand, six hundred twelve".