115509 has 8 divisors (see below), whose sum is σ = 155680. Its totient is φ = 76176.

The previous prime is 115499. The next prime is 115513. The reversal of 115509 is 905511.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 115509 - 2⁹ = 114997 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 (115589) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279 + ... + 555.

It is an arithmetic number, because the mean of its divisors is an integer number (19460).

2¹¹⁵⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

115509 is a deficient number, since it is larger than the sum of its proper divisors (40171).

115509 is a wasteful number, since it uses less digits than its factorization.

115509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419.

The product of its (nonzero) digits is 225, while the sum is 21.

The square root of 115509 is about 339.8661501238. The cubic root of 115509 is about 48.7010817643.

The spelling of 115509 in words is "one hundred fifteen thousand, five hundred nine".