1156105309561 has 2 divisors, whose sum is σ = 1156105309562. Its totient is φ = 1156105309560.

The previous prime is 1156105309537. The next prime is 1156105309571. The reversal of 1156105309561 is 1659035016511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1148206543936 + 7898765625 = 1071544^2 + 88875^2 .

It is a cyclic number.

It is not a de Polignac number, because 1156105309561 - 2⁵ = 1156105309529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1156105309571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 578052654780 + 578052654781.

It is an arithmetic number, because the mean of its divisors is an integer number (578052654781).

Almost surely, 2^{1156105309561} is an apocalyptic number.

It is an amenable number.

1156105309561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1156105309561 is an equidigital number, since it uses as much as digits as its factorization.

1156105309561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 121500, while the sum is 43.

The spelling of 1156105309561 in words is "one trillion, one hundred fifty-six billion, one hundred five million, three hundred nine thousand, five hundred sixty-one".