165115509 has 32 divisors (see below), whose sum is σ = 252120960. Its totient is φ = 95219712.

The previous prime is 165115477. The next prime is 165115547. The reversal of 165115509 is 905511561.

It is not a de Polignac number, because 165115509 - 2⁵ = 165115477 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 165115509.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165115109) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 223062 + ... + 223800.

It is an arithmetic number, because the mean of its divisors is an integer number (7878780).

Almost surely, 2^165115509 is an apocalyptic number.

It is an amenable number.

165115509 is a deficient number, since it is larger than the sum of its proper divisors (87005451).

165115509 is a wasteful number, since it uses less digits than its factorization.

165115509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1109.

The product of its (nonzero) digits is 6750, while the sum is 33.

The square root of 165115509 is about 12849.7279737744. The cubic root of 165115509 is about 548.6086141804.

The spelling of 165115509 in words is "one hundred sixty-five million, one hundred fifteen thousand, five hundred nine".