12991781376 has 160 divisors (see below), whose sum is σ = 43950698880. Its totient is φ = 3711909888.

The previous prime is 12991781353. The next prime is 12991781381. The reversal of 12991781376 is 67318719921.

It is a happy number.

12991781376 is a `hidden beast` number, since 12 + 99 + 178 + 1 + 376 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

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, 29640 + ... + 163896.

It is an arithmetic number, because the mean of its divisors is an integer number (274691868).

Almost surely, 2^12991781376 is an apocalyptic number.

12991781376 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12991781376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21975349440).

12991781376 is an abundant number, since it is smaller than the sum of its proper divisors (30958917504).

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

12991781376 is an equidigital number, since it uses as much as digits as its factorization.

12991781376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134291 (or 134269 counting only the distinct ones).

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

The spelling of 12991781376 in words is "twelve billion, nine hundred ninety-one million, seven hundred eighty-one thousand, three hundred seventy-six".