165165109 has 4 divisors (see below), whose sum is σ = 165407616. Its totient is φ = 164922604.

The previous prime is 165165073. The next prime is 165165113. The reversal of 165165109 is 901561561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165165109 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 (165165509) 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, 120229 + ... + 121594.

It is an arithmetic number, because the mean of its divisors is an integer number (41351904).

Almost surely, 2^165165109 is an apocalyptic number.

It is an amenable number.

165165109 is a deficient number, since it is larger than the sum of its proper divisors (242507).

165165109 is an equidigital number, since it uses as much as digits as its factorization.

165165109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242506.

The product of its (nonzero) digits is 8100, while the sum is 34.

The square root of 165165109 is about 12851.6578308014. The cubic root of 165165109 is about 548.6635419160.

The spelling of 165165109 in words is "one hundred sixty-five million, one hundred sixty-five thousand, one hundred nine".