165111611 has 16 divisors (see below), whose sum is σ = 198942720. Its totient is φ = 134036640.

The previous prime is 165111601. The next prime is 165111613. The reversal of 165111611 is 116111561.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165111611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165111613) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2105 + ... + 18293.

It is an arithmetic number, because the mean of its divisors is an integer number (12433920).

Almost surely, 2^165111611 is an apocalyptic number.

165111611 is a deficient number, since it is larger than the sum of its proper divisors (33831109).

165111611 is a wasteful number, since it uses less digits than its factorization.

165111611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16274.

The product of its digits is 180, while the sum is 23.

The square root of 165111611 is about 12849.5762965166. The cubic root of 165111611 is about 548.6042970144.

Subtracting from 165111611 its reverse (116111561), we obtain a triangular number (49000050 = T₉₈₉₉).

The spelling of 165111611 in words is "one hundred sixty-five million, one hundred eleven thousand, six hundred eleven".