12513816864 has 36 divisors (see below), whose sum is σ = 35586167526. Its totient is φ = 4171272192.

The previous prime is 12513816863. The next prime is 12513816893. The reversal of 12513816864 is 46861831521.

12513816864 is a `hidden beast` number, since 12 + 513 + 8 + 1 + 68 + 64 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12227936400 + 285880464 = 110580^2 + 16908^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×12513816864² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12513816863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21725089 + ... + 21725664.

Almost surely, 2^12513816864 is an apocalyptic number.

It is an amenable number.

12513816864 is an abundant number, since it is smaller than the sum of its proper divisors (23072350662).

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

12513816864 is a wasteful number, since it uses less digits than its factorization.

12513816864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43450769 (or 43450758 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The spelling of 12513816864 in words is "twelve billion, five hundred thirteen million, eight hundred sixteen thousand, eight hundred sixty-four".