12647476521 has 27 divisors (see below), whose sum is σ = 19290463959. Its totient is φ = 7983831312.

The previous prime is 12647476507. The next prime is 12647476529. The reversal of 12647476521 is 12567474621.

The square root of 12647476521 is 112461.

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

12647476521 is a `hidden beast` number, since 12 + 6 + 47 + 4 + 76 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2720144025 + 9927332496 = 52155^2 + 99636^2 .

It is not a de Polignac number, because 12647476521 - 2⁷ = 12647476393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12647476529) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 6409291 + ... + 6411263.

Almost surely, 2^12647476521 is an apocalyptic number.

12647476521 is the 112461-st square number.

12647476521 is the 56231-st centered octagonal number.

It is an amenable number.

12647476521 is a deficient number, since it is larger than the sum of its proper divisors (6642987438).

12647476521 is an frugal number, since it uses more digits than its factorization.

12647476521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3990 (or 1995 counting only the distinct ones).

The product of its digits is 564480, while the sum is 45.

The spelling of 12647476521 in words is "twelve billion, six hundred forty-seven million, four hundred seventy-six thousand, five hundred twenty-one".