12991857792 has 32 divisors (see below), whose sum is σ = 34509623280. Its totient is φ = 4330619136.

The previous prime is 12991857779. The next prime is 12991857883. The reversal of 12991857792 is 29775819921.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-2 number, since 2×12991857792² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16916098 + ... + 16916865.

Almost surely, 2^12991857792 is an apocalyptic number.

12991857792 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

12991857792 is an abundant number, since it is smaller than the sum of its proper divisors (21517765488).

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

12991857792 is an equidigital number, since it uses as much as digits as its factorization.

12991857792 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33832980 (or 33832968 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 60.

The spelling of 12991857792 in words is "twelve billion, nine hundred ninety-one million, eight hundred fifty-seven thousand, seven hundred ninety-two".