12561338880 has 480 divisors, whose sum is σ = 46063480320. Its totient is φ = 3158507520.

The previous prime is 12561338821. The next prime is 12561338903. The reversal of 12561338880 is 8883316521.

12561338880 is a `hidden beast` number, since 1 + 2 + 561 + 3 + 3 + 8 + 8 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 30712116 + ... + 30712524.

It is an arithmetic number, because the mean of its divisors is an integer number (95965584).

Almost surely, 2^12561338880 is an apocalyptic number.

12561338880 is a gapful number since it is divisible by the number (10) 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 12561338880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23031740160).

12561338880 is an abundant number, since it is smaller than the sum of its proper divisors (33502141440).

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

12561338880 is a wasteful number, since it uses less digits than its factorization.

12561338880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 45.

The spelling of 12561338880 in words is "twelve billion, five hundred sixty-one million, three hundred thirty-eight thousand, eight hundred eighty".