165405219839 has 4 divisors (see below), whose sum is σ = 169875631224. Its totient is φ = 160934808456.

The previous prime is 165405219803. The next prime is 165405219869. The reversal of 165405219839 is 938912504561.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165405219839 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 (165405219869) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2235205637 + ... + 2235205710.

It is an arithmetic number, because the mean of its divisors is an integer number (42468907806).

Almost surely, 2^165405219839 is an apocalyptic number.

165405219839 is a deficient number, since it is larger than the sum of its proper divisors (4470411385).

165405219839 is an equidigital number, since it uses as much as digits as its factorization.

165405219839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4470411384.

The product of its (nonzero) digits is 2332800, while the sum is 53.

The spelling of 165405219839 in words is "one hundred sixty-five billion, four hundred five million, two hundred nineteen thousand, eight hundred thirty-nine".