12565561 has 2 divisors, whose sum is σ = 12565562. Its totient is φ = 12565560.

The previous prime is 12565549. The next prime is 12565603. The reversal of 12565561 is 16556521.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12559936 + 5625 = 3544^2 + 75^2 .

It is a cyclic number.

It is not a de Polignac number, because 12565561 - 2⁷ = 12565433 is a prime.

It is not a weakly prime, because it can be changed into another prime (12565541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6282780 + 6282781.

It is an arithmetic number, because the mean of its divisors is an integer number (6282781).

Almost surely, 2^12565561 is an apocalyptic number.

It is an amenable number.

12565561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12565561 is an equidigital number, since it uses as much as digits as its factorization.

12565561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9000, while the sum is 31.

The square root of 12565561 is about 3544.7935059746. The cubic root of 12565561 is about 232.4844773234.

The spelling of 12565561 in words is "twelve million, five hundred sixty-five thousand, five hundred sixty-one".