165191855 has 4 divisors (see below), whose sum is σ = 198230232. Its totient is φ = 132153480.

The previous prime is 165191849. The next prime is 165191881. The reversal of 165191855 is 558191561.

165191855 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 558191561 = 10993 ⋅50777.

It is not a de Polignac number, because 165191855 - 2²⁶ = 98082991 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16519181 + ... + 16519190.

It is an arithmetic number, because the mean of its divisors is an integer number (49557558).

Almost surely, 2^165191855 is an apocalyptic number.

165191855 is a deficient number, since it is larger than the sum of its proper divisors (33038377).

165191855 is an equidigital number, since it uses as much as digits as its factorization.

165191855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33038376.

The product of its digits is 54000, while the sum is 41.

The square root of 165191855 is about 12852.6983548203. The cubic root of 165191855 is about 548.6931562478.

The spelling of 165191855 in words is "one hundred sixty-five million, one hundred ninety-one thousand, eight hundred fifty-five".