12561681 has 8 divisors (see below), whose sum is σ = 18271584. Its totient is φ = 7613120.

The previous prime is 12561671. The next prime is 12561701. The reversal of 12561681 is 18616521.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12561681 - 2¹⁵ = 12528913 is a prime.

It is a super-2 number, since 2×12561681² = 315591659091522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12561671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 190296 + ... + 190361.

It is an arithmetic number, because the mean of its divisors is an integer number (2283948).

Almost surely, 2^12561681 is an apocalyptic number.

12561681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12561681 is a deficient number, since it is larger than the sum of its proper divisors (5709903).

12561681 is a wasteful number, since it uses less digits than its factorization.

12561681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380671.

The product of its digits is 2880, while the sum is 30.

The square root of 12561681 is about 3544.2461821945. The cubic root of 12561681 is about 232.4605459703.

The spelling of 12561681 in words is "twelve million, five hundred sixty-one thousand, six hundred eighty-one".