165918165 has 72 divisors (see below), whose sum is σ = 328073760. Its totient is φ = 71197056.

The previous prime is 165918157. The next prime is 165918167. The reversal of 165918165 is 561819561.

It is not a de Polignac number, because 165918165 - 2³ = 165918157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165918167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1522131 + ... + 1522239.

It is an arithmetic number, because the mean of its divisors is an integer number (4556580).

Almost surely, 2^165918165 is an apocalyptic number.

165918165 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165918165 is a deficient number, since it is larger than the sum of its proper divisors (162155595).

165918165 is a wasteful number, since it uses less digits than its factorization.

165918165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259 (or 143 counting only the distinct ones).

The product of its digits is 64800, while the sum is 42.

The square root of 165918165 is about 12880.9225213103. The cubic root of 165918165 is about 549.4961390995.

The spelling of 165918165 in words is "one hundred sixty-five million, nine hundred eighteen thousand, one hundred sixty-five".