165021 has 8 divisors (see below), whose sum is σ = 223584. Its totient is φ = 108240.

The previous prime is 165001. The next prime is 165037. The reversal of 165021 is 120561.

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

It is not a de Polignac number, because 165021 - 2⁷ = 164893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165001) 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, 210 + ... + 611.

It is an arithmetic number, because the mean of its divisors is an integer number (27948).

2¹⁶⁵⁰²¹ is an apocalyptic number.

It is an amenable number.

165021 is a deficient number, since it is larger than the sum of its proper divisors (58563).

165021 is an equidigital number, since it uses as much as digits as its factorization.

165021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 165021 is about 406.2277686225. The cubic root of 165021 is about 54.8503923132.

Adding to 165021 its reverse (120561), we get a palindrome (285582).

The spelling of 165021 in words is "one hundred sixty-five thousand, twenty-one".