12917981818 has 24 divisors (see below), whose sum is σ = 22965862932. Its totient is φ = 5431817664.

The previous prime is 12917981789. The next prime is 12917981831. The reversal of 12917981818 is 81818971921.

It can be written as a sum of positive squares in 2 ways, for example, as 12873852369 + 44129449 = 113463^2 + 6643^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1238355 + ... + 1248742.

Almost surely, 2^12917981818 is an apocalyptic number.

12917981818 is a deficient number, since it is larger than the sum of its proper divisors (10047881114).

12917981818 is a wasteful number, since it uses less digits than its factorization.

12917981818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2487166 (or 2487159 counting only the distinct ones).

The product of its digits is 580608, while the sum is 55.

The spelling of 12917981818 in words is "twelve billion, nine hundred seventeen million, nine hundred eighty-one thousand, eight hundred eighteen".