12561550056 has 96 divisors (see below), whose sum is σ = 37273504320. Its totient is φ = 3790137600.

The previous prime is 12561550051. The next prime is 12561550103. The reversal of 12561550056 is 65005516521.

12561550056 is a `hidden beast` number, since 1 + 2 + 56 + 1 + 550 + 0 + 56 = 666.

12561550056 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 12561550056.

It is not an unprimeable number, because it can be changed into a prime (12561550051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 150501 + ... + 218571.

It is an arithmetic number, because the mean of its divisors is an integer number (388265670).

Almost surely, 2^12561550056 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12561550056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18636752160).

12561550056 is an abundant number, since it is smaller than the sum of its proper divisors (24711954264).

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

12561550056 is a wasteful number, since it uses less digits than its factorization.

12561550056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68327 (or 68320 counting only the distinct ones).

The product of its (nonzero) digits is 45000, while the sum is 36.

The spelling of 12561550056 in words is "twelve billion, five hundred sixty-one million, five hundred fifty thousand, fifty-six".