12978691317 has 30 divisors (see below), whose sum is σ = 19921492514. Its totient is φ = 8414565120.

The previous prime is 12978691307. The next prime is 12978691373. The reversal of 12978691317 is 71319687921.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 2960883396 + 10017807921 = 54414^2 + 100089^2 .

It is not a de Polignac number, because 12978691317 - 2⁷ = 12978691189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12978691307) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 6235717 + ... + 6237797.

Almost surely, 2^12978691317 is an apocalyptic number.

It is an amenable number.

12978691317 is a deficient number, since it is larger than the sum of its proper divisors (6942801197).

12978691317 is an frugal number, since it uses more digits than its factorization.

12978691317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4211 (or 2121 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The spelling of 12978691317 in words is "twelve billion, nine hundred seventy-eight million, six hundred ninety-one thousand, three hundred seventeen".