115205561 has 2 divisors, whose sum is σ = 115205562. Its totient is φ = 115205560.

The previous prime is 115205513. The next prime is 115205567. The reversal of 115205561 is 165502511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97397161 + 17808400 = 9869^2 + 4220^2 .

It is a cyclic number.

It is not a de Polignac number, because 115205561 - 2¹⁸ = 114943417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 115205561.

It is not a weakly prime, because it can be changed into another prime (115205567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 57602780 + 57602781.

It is an arithmetic number, because the mean of its divisors is an integer number (57602781).

Almost surely, 2^115205561 is an apocalyptic number.

It is an amenable number.

115205561 is a deficient number, since it is larger than the sum of its proper divisors (1).

115205561 is an equidigital number, since it uses as much as digits as its factorization.

115205561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1500, while the sum is 26.

The square root of 115205561 is about 10733.3853466649. The cubic root of 115205561 is about 486.5839889470.

The spelling of 115205561 in words is "one hundred fifteen million, two hundred five thousand, five hundred sixty-one".