165644423 has 4 divisors (see below), whose sum is σ = 189307920. Its totient is φ = 141980928.

The previous prime is 165644419. The next prime is 165644429. The reversal of 165644423 is 324446561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 324446561 = 647 ⋅501463.

It is a cyclic number.

It is not a de Polignac number, because 165644423 - 2² = 165644419 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 (165644429) 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, 11831738 + ... + 11831751.

It is an arithmetic number, because the mean of its divisors is an integer number (47326980).

Almost surely, 2^165644423 is an apocalyptic number.

165644423 is a deficient number, since it is larger than the sum of its proper divisors (23663497).

165644423 is an equidigital number, since it uses as much as digits as its factorization.

165644423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23663496.

The product of its digits is 69120, while the sum is 35.

The square root of 165644423 is about 12870.2922655237. The cubic root of 165644423 is about 549.1937752361.

The spelling of 165644423 in words is "one hundred sixty-five million, six hundred forty-four thousand, four hundred twenty-three".