12561120786816 has 1024 divisors, whose sum is σ = 46550384640000. Its totient is φ = 3251736576000.

The previous prime is 12561120786787. The next prime is 12561120786817. The reversal of 12561120786816 is 61868702116521.

12561120786816 is a `hidden beast` number, since 1 + 2 + 5 + 611 + 2 + 0 + 7 + 8 + 6 + 8 + 16 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12561120786817) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2537085141 + ... + 2537090091.

It is an arithmetic number, because the mean of its divisors is an integer number (45459360000).

Almost surely, 2^{12561120786816} is an apocalyptic number.

12561120786816 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 12561120786816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23275192320000).

12561120786816 is an abundant number, since it is smaller than the sum of its proper divisors (33989263853184).

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

12561120786816 is a wasteful number, since it uses less digits than its factorization.

12561120786816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5228 (or 5210 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 54.

The spelling of 12561120786816 in words is "twelve trillion, five hundred sixty-one billion, one hundred twenty million, seven hundred eighty-six thousand, eight hundred sixteen".