11561625961 has 2 divisors, whose sum is σ = 11561625962. Its totient is φ = 11561625960.

The previous prime is 11561625917. The next prime is 11561625983. The reversal of 11561625961 is 16952616511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11525096025 + 36529936 = 107355^2 + 6044^2 .

It is a cyclic number.

It is not a de Polignac number, because 11561625961 - 2¹⁵ = 11561593193 is a prime.

It is not a weakly prime, because it can be changed into another prime (11561625461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5780812980 + 5780812981.

It is an arithmetic number, because the mean of its divisors is an integer number (5780812981).

Almost surely, 2^11561625961 is an apocalyptic number.

It is an amenable number.

11561625961 is a deficient number, since it is larger than the sum of its proper divisors (1).

11561625961 is an equidigital number, since it uses as much as digits as its factorization.

11561625961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 97200, while the sum is 43.

The spelling of 11561625961 in words is "eleven billion, five hundred sixty-one million, six hundred twenty-five thousand, nine hundred sixty-one".