12656717440 has 32 divisors (see below), whose sum is σ = 30257466660. Its totient is φ = 5062686720.

The previous prime is 12656717387. The next prime is 12656717483. The reversal of 12656717440 is 4471765621.

It can be written as a sum of positive squares in 2 ways, for example, as 12221744704 + 434972736 = 110552^2 + 20856^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9887421 + ... + 9888700.

Almost surely, 2^12656717440 is an apocalyptic number.

12656717440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12656717440 is an abundant number, since it is smaller than the sum of its proper divisors (17600749220).

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

12656717440 is an equidigital number, since it uses as much as digits as its factorization.

12656717440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19776140 (or 19776128 counting only the distinct ones).

The product of its (nonzero) digits is 282240, while the sum is 43.

The spelling of 12656717440 in words is "twelve billion, six hundred fifty-six million, seven hundred seventeen thousand, four hundred forty".