12991259456 has 112 divisors (see below), whose sum is σ = 31101792000. Its totient is φ = 5375430144.

The previous prime is 12991259419. The next prime is 12991259509. The reversal of 12991259456 is 65495219921.

It is a tau number, because it is divible by the number of its divisors (112).

It is a junction number, because it is equal to n+sod(n) for n = 12991259398 and 12991259407.

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, 626405 + ... + 646811.

Almost surely, 2^12991259456 is an apocalyptic number.

12991259456 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 12991259456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15550896000).

12991259456 is an abundant number, since it is smaller than the sum of its proper divisors (18110532544).

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

12991259456 is an equidigital number, since it uses as much as digits as its factorization.

12991259456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20469 (or 20445 counting only the distinct ones).

The product of its digits is 1749600, while the sum is 53.

The spelling of 12991259456 in words is "twelve billion, nine hundred ninety-one million, two hundred fifty-nine thousand, four hundred fifty-six".