20239 has 4 divisors (see below), whose sum is σ = 20824. Its totient is φ = 19656.

The previous prime is 20233. The next prime is 20249. The reversal of 20239 is 93202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93202 = 2 ⋅46601.

It is a cyclic number.

It is not a de Polignac number, because 20239 - 2³ = 20231 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 (20231) 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, 237 + ... + 310.

It is an arithmetic number, because the mean of its divisors is an integer number (5206).

2²⁰²³⁹ is an apocalyptic number.

20239 is a deficient number, since it is larger than the sum of its proper divisors (585).

20239 is an equidigital number, since it uses as much as digits as its factorization.

20239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 20239 is about 142.2638393971. The cubic root of 20239 is about 27.2518726093.

Multiplying 20239 by its product of nonzero digits (108), we get a palindrome (2185812).

The spelling of 20239 in words is "twenty thousand, two hundred thirty-nine".