12561488416521 has 64 divisors (see below), whose sum is σ = 20857884691200. Its totient is φ = 7404493824000.

The previous prime is 12561488416517. The next prime is 12561488416523.

12561488416521 is a `hidden beast` number, since 1 + 2 + 5 + 61 + 48 + 8 + 4 + 16 + 521 = 666.

12561488416521 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 12561488416521 - 2² = 12561488416517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (12561488416523) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 29336871 + ... + 29761971.

It is an arithmetic number, because the mean of its divisors is an integer number (325904448300).

Almost surely, 2^{12561488416521} is an apocalyptic number.

12561488416521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12561488416521 is a deficient number, since it is larger than the sum of its proper divisors (8296396274679).

12561488416521 is a wasteful number, since it uses less digits than its factorization.

12561488416521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427847 (or 427841 counting only the distinct ones).

The product of its digits is 3686400, while the sum is 54.

The spelling of 12561488416521 in words is "twelve trillion, five hundred sixty-one billion, four hundred eighty-eight million, four hundred sixteen thousand, five hundred twenty-one".