12991781375 has 16 divisors (see below), whose sum is σ = 16221434112. Its totient is φ = 10388495200.

The previous prime is 12991781353. The next prime is 12991781381. The reversal of 12991781375 is 57318719921.

It is a happy number.

It is not a de Polignac number, because 12991781375 - 2⁸ = 12991781119 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 252329 + ... + 299421.

It is an arithmetic number, because the mean of its divisors is an integer number (1013839632).

Almost surely, 2^12991781375 is an apocalyptic number.

12991781375 is a deficient number, since it is larger than the sum of its proper divisors (3229652737).

12991781375 is an equidigital number, since it uses as much as digits as its factorization.

12991781375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49315 (or 49305 counting only the distinct ones).

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

The spelling of 12991781375 in words is "twelve billion, nine hundred ninety-one million, seven hundred eighty-one thousand, three hundred seventy-five".