12561065591 has 2 divisors, whose sum is σ = 12561065592. Its totient is φ = 12561065590.

The previous prime is 12561065563. The next prime is 12561065593. The reversal of 12561065591 is 19556016521.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 12561065591 - 2³⁰ = 11487323767 is a prime.

Together with 12561065593, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12561065593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6280532795 + 6280532796.

It is an arithmetic number, because the mean of its divisors is an integer number (6280532796).

Almost surely, 2^12561065591 is an apocalyptic number.

12561065591 is a deficient number, since it is larger than the sum of its proper divisors (1).

12561065591 is an equidigital number, since it uses as much as digits as its factorization.

12561065591 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81000, while the sum is 41.

The spelling of 12561065591 in words is "twelve billion, five hundred sixty-one million, sixty-five thousand, five hundred ninety-one".