115555509 has 6 divisors (see below), whose sum is σ = 166913526. Its totient is φ = 77037000.

The previous prime is 115555501. The next prime is 115555513. The reversal of 115555509 is 905555511.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 108680625 + 6874884 = 10425^2 + 2622^2 .

It is not a de Polignac number, because 115555509 - 2³ = 115555501 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115555501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6419742 + ... + 6419759.

It is an arithmetic number, because the mean of its divisors is an integer number (27818921).

Almost surely, 2^115555509 is an apocalyptic number.

It is an amenable number.

115555509 is a deficient number, since it is larger than the sum of its proper divisors (51358017).

115555509 is a wasteful number, since it uses less digits than its factorization.

115555509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12839507 (or 12839504 counting only the distinct ones).

The product of its (nonzero) digits is 28125, while the sum is 36.

The square root of 115555509 is about 10749.6748322914. The cubic root of 115555509 is about 487.0761728590.

The spelling of 115555509 in words is "one hundred fifteen million, five hundred fifty-five thousand, five hundred nine".