12616981057521 has 63 divisors (see below), whose sum is σ = 19023970267249. Its totient is φ = 8363943608832.

The previous prime is 12616981057511. The next prime is 12616981057537. The reversal of 12616981057521 is 12575018961621.

The square root of 12616981057521 is 3552039.

It is a perfect power (a square), and thus also a powerful number.

12616981057521 is a `hidden beast` number, since 1 + 2 + 6 + 1 + 6 + 9 + 8 + 105 + 7 + 521 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4782378528225 + 7834602529296 = 2186865^2 + 2799036^2 .

It is not a de Polignac number, because 12616981057521 - 2¹¹ = 12616981055473 is a prime.

It is a super-2 number, since 2×12616981057521² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12616981057511) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 28100180305 + ... + 28100180753.

Almost surely, 2^{12616981057521} is an apocalyptic number.

12616981057521 is the 3552039-th square number.

12616981057521 is the 1776020-th centered octagonal number.

It is an amenable number.

12616981057521 is a deficient number, since it is larger than the sum of its proper divisors (6406989209728).

12616981057521 is an frugal number, since it uses more digits than its factorization.

12616981057521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1502 (or 745 counting only the distinct ones).

The product of its (nonzero) digits is 1814400, while the sum is 54.

The spelling of 12616981057521 in words is "twelve trillion, six hundred sixteen billion, nine hundred eighty-one million, fifty-seven thousand, five hundred twenty-one".