165220023 has 4 divisors (see below), whose sum is σ = 220293368. Its totient is φ = 110146680.

The previous prime is 165220021. The next prime is 165220039. The reversal of 165220023 is 320022561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 320022561 = 3 ⋅106674187.

It is not a de Polignac number, because 165220023 - 2¹ = 165220021 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 (165220021) 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, 27536668 + ... + 27536673.

It is an arithmetic number, because the mean of its divisors is an integer number (55073342).

Almost surely, 2^165220023 is an apocalyptic number.

165220023 is a deficient number, since it is larger than the sum of its proper divisors (55073345).

165220023 is an equidigital number, since it uses as much as digits as its factorization.

165220023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55073344.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 165220023 is about 12853.7941091337. The cubic root of 165220023 is about 548.7243416240.

Adding to 165220023 its reverse (320022561), we get a palindrome (485242584).

The spelling of 165220023 in words is "one hundred sixty-five million, two hundred twenty thousand, twenty-three".