115115656501561 has 2 divisors, whose sum is σ = 115115656501562. Its totient is φ = 115115656501560.

The previous prime is 115115656501493. The next prime is 115115656501589. The reversal of 115115656501561 is 165105656511511.

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., 112930344743161 + 2185311758400 = 10626869^2 + 1478280^2 .

It is a cyclic number.

It is not a de Polignac number, because 115115656501561 - 2¹⁵ = 115115656468793 is a prime.

It is a super-2 number, since 2×115115656501561² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (115115656571561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57557828250780 + 57557828250781.

It is an arithmetic number, because the mean of its divisors is an integer number (57557828250781).

Almost surely, 2^{115115656501561} is an apocalyptic number.

It is an amenable number.

115115656501561 is a deficient number, since it is larger than the sum of its proper divisors (1).

115115656501561 is an equidigital number, since it uses as much as digits as its factorization.

115115656501561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 675000, while the sum is 49.

The spelling of 115115656501561 in words is "one hundred fifteen trillion, one hundred fifteen billion, six hundred fifty-six million, five hundred one thousand, five hundred sixty-one".