13172978915 has 4 divisors (see below), whose sum is σ = 15807574704. Its totient is φ = 10538383128.

The previous prime is 13172978869. The next prime is 13172978927. The reversal of 13172978915 is 51987927131.

It is a happy number.

13172978915 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51987927131 = 7 ⋅7426846733.

It is a cyclic number.

It is not a de Polignac number, because 13172978915 - 2²² = 13168784611 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1317297887 + ... + 1317297896.

It is an arithmetic number, because the mean of its divisors is an integer number (3951893676).

Almost surely, 2^13172978915 is an apocalyptic number.

13172978915 is a deficient number, since it is larger than the sum of its proper divisors (2634595789).

13172978915 is an equidigital number, since it uses as much as digits as its factorization.

13172978915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2634595788.

The product of its digits is 952560, while the sum is 53.

The spelling of 13172978915 in words is "thirteen billion, one hundred seventy-two million, nine hundred seventy-eight thousand, nine hundred fifteen".