165195791 has 4 divisors (see below), whose sum is σ = 165917400. Its totient is φ = 164474184.

The previous prime is 165195781. The next prime is 165195799. The reversal of 165195791 is 197591561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165195791 - 2⁶ = 165195727 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165195799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360461 + ... + 360918.

It is an arithmetic number, because the mean of its divisors is an integer number (41479350).

Almost surely, 2^165195791 is an apocalyptic number.

165195791 is a deficient number, since it is larger than the sum of its proper divisors (721609).

165195791 is an equidigital number, since it uses as much as digits as its factorization.

165195791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 721608.

The product of its digits is 85050, while the sum is 44.

The square root of 165195791 is about 12852.8514735058. The cubic root of 165195791 is about 548.6975140880.

The spelling of 165195791 in words is "one hundred sixty-five million, one hundred ninety-five thousand, seven hundred ninety-one".