12931328656 has 15 divisors (see below), whose sum is σ = 25055330601. Its totient is φ = 6465436896.

The previous prime is 12931328621. The next prime is 12931328659. The reversal of 12931328656 is 65682313921.

The square root of 12931328656 is 113716.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 4393568656 + 8537760000 = 66284^2 + 92400^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12931328659) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 440650 + ... + 469078.

Almost surely, 2^12931328656 is an apocalyptic number.

12931328656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

12931328656 is the 113716-th square number.

It is an amenable number.

12931328656 is a deficient number, since it is larger than the sum of its proper divisors (12124001945).

12931328656 is an frugal number, since it uses more digits than its factorization.

12931328656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56866 (or 28431 counting only the distinct ones).

The product of its digits is 466560, while the sum is 46.

The spelling of 12931328656 in words is "twelve billion, nine hundred thirty-one million, three hundred twenty-eight thousand, six hundred fifty-six".