12491638756 has 81 divisors (see below), whose sum is σ = 23710080667. Its totient is φ = 5758184320.

The previous prime is 12491638729. The next prime is 12491638793. The reversal of 12491638756 is 65783619421.

The square root of 12491638756 is 111766.

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

It can be written as a sum of positive squares in 4 ways, for example, as 3298664356 + 9192974400 = 57434^2 + 95880^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 265779525 + ... + 265779571.

Almost surely, 2^12491638756 is an apocalyptic number.

12491638756 is the 111766-th square number.

It is an amenable number.

12491638756 is a deficient number, since it is larger than the sum of its proper divisors (11218441911).

12491638756 is an equidigital number, since it uses as much as digits as its factorization.

12491638756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 238 (or 119 counting only the distinct ones).

The product of its digits is 2177280, while the sum is 52.

The spelling of 12491638756 in words is "twelve billion, four hundred ninety-one million, six hundred thirty-eight thousand, seven hundred fifty-six".