12564393894 has 120 divisors (see below), whose sum is σ = 30777884280. Its totient is φ = 3828943872.

The previous prime is 12564393887. The next prime is 12564393917. The reversal of 12564393894 is 49839346521.

12564393894 is a `hidden beast` number, since 1 + 256 + 4 + 3 + 9 + 389 + 4 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 12564393894.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2927302 + ... + 2931590.

It is an arithmetic number, because the mean of its divisors is an integer number (256482369).

Almost surely, 2^12564393894 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12564393894, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15388942140).

12564393894 is an abundant number, since it is smaller than the sum of its proper divisors (18213490386).

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

12564393894 is a wasteful number, since it uses less digits than its factorization.

12564393894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4436 (or 4414 counting only the distinct ones).

The product of its digits is 5598720, while the sum is 54.

The spelling of 12564393894 in words is "twelve billion, five hundred sixty-four million, three hundred ninety-three thousand, eight hundred ninety-four".