115661509 has 8 divisors (see below), whose sum is σ = 116395200. Its totient is φ = 114930816.

The previous prime is 115661467. The next prime is 115661537. The reversal of 115661509 is 905166511.

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

It is a cyclic number.

It is not a de Polignac number, because 115661509 - 2¹¹ = 115659461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (115661009) 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, 192792 + ... + 193390.

It is an arithmetic number, because the mean of its divisors is an integer number (14549400).

Almost surely, 2^115661509 is an apocalyptic number.

It is an amenable number.

115661509 is a deficient number, since it is larger than the sum of its proper divisors (733691).

115661509 is an equidigital number, since it uses as much as digits as its factorization.

115661509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1499.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 115661509 is about 10754.6040838331. The cubic root of 115661509 is about 487.2250603098.

The spelling of 115661509 in words is "one hundred fifteen million, six hundred sixty-one thousand, five hundred nine".