12399566256 has 240 divisors, whose sum is σ = 43859811840. Its totient is φ = 3176340480.

The previous prime is 12399566243. The next prime is 12399566261. The reversal of 12399566256 is 65266599321.

It is a happy number.

12399566256 is a `hidden beast` number, since 1 + 2 + 3 + 9 + 9 + 5 + 6 + 625 + 6 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 801765 + ... + 817083.

It is an arithmetic number, because the mean of its divisors is an integer number (182749216).

Almost surely, 2^12399566256 is an apocalyptic number.

12399566256 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 12399566256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21929905920).

12399566256 is an abundant number, since it is smaller than the sum of its proper divisors (31460245584).

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

12399566256 is a wasteful number, since it uses less digits than its factorization.

12399566256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15424 (or 15415 counting only the distinct ones).

The product of its digits is 5248800, while the sum is 54.

The spelling of 12399566256 in words is "twelve billion, three hundred ninety-nine million, five hundred sixty-six thousand, two hundred fifty-six".