165915915 has 16 divisors (see below), whose sum is σ = 289598976. Its totient is φ = 80444000.

The previous prime is 165915901. The next prime is 165915943. The reversal of 165915915 is 519519561.

It is not a de Polignac number, because 165915915 - 2⁴ = 165915899 is a prime.

It is a nialpdrome in base 15.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 502611 + ... + 502940.

It is an arithmetic number, because the mean of its divisors is an integer number (18099936).

Almost surely, 2^165915915 is an apocalyptic number.

165915915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

165915915 is a deficient number, since it is larger than the sum of its proper divisors (123683061).

165915915 is a wasteful number, since it uses less digits than its factorization.

165915915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1005570.

The product of its digits is 60750, while the sum is 42.

The square root of 165915915 is about 12880.8351825493. The cubic root of 165915915 is about 549.4936552005.

The spelling of 165915915 in words is "one hundred sixty-five million, nine hundred fifteen thousand, nine hundred fifteen".