165023021 has 8 divisors (see below), whose sum is σ = 172876800. Its totient is φ = 157313520.

The previous prime is 165023017. The next prime is 165023069. The reversal of 165023021 is 120320561.

165023021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165023021 - 2² = 165023017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 165022984 and 165023002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165023921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33725 + ... + 38306.

It is an arithmetic number, because the mean of its divisors is an integer number (21609600).

Almost surely, 2^165023021 is an apocalyptic number.

It is an amenable number.

165023021 is a deficient number, since it is larger than the sum of its proper divisors (7853779).

165023021 is an equidigital number, since it uses as much as digits as its factorization.

165023021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72139.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 165023021 is about 12846.1286386211. The cubic root of 165023021 is about 548.5061622857.

Adding to 165023021 its reverse (120320561), we get a palindrome (285343582).

The spelling of 165023021 in words is "one hundred sixty-five million, twenty-three thousand, twenty-one".