12511561 has 2 divisors, whose sum is σ = 12511562. Its totient is φ = 12511560.

The previous prime is 12511553. The next prime is 12511567. The reversal of 12511561 is 16511521.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11799225 + 712336 = 3435^2 + 844^2 .

It is a cyclic number.

It is not a de Polignac number, because 12511561 - 2³ = 12511553 is a prime.

It is not a weakly prime, because it can be changed into another prime (12511567) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6255780 + 6255781.

It is an arithmetic number, because the mean of its divisors is an integer number (6255781).

Almost surely, 2^12511561 is an apocalyptic number.

It is an amenable number.

12511561 is a deficient number, since it is larger than the sum of its proper divisors (1).

12511561 is an equidigital number, since it uses as much as digits as its factorization.

12511561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 300, while the sum is 22.

The square root of 12511561 is about 3537.1685003686. The cubic root of 12511561 is about 232.1509681787.

The spelling of 12511561 in words is "twelve million, five hundred eleven thousand, five hundred sixty-one".