20023 has 2 divisors, whose sum is σ = 20024. Its totient is φ = 20022.

The previous prime is 20021. The next prime is 20029. The reversal of 20023 is 32002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20023 - 2¹ = 20021 is a prime.

Together with 20021, it forms a pair of twin primes.

It is the 142-nd Hogben number.

It is a junction number, because it is equal to n+sod(n) for n = 19988 and 20015.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20021) by changing a digit.

It is a nontrivial repunit in base 141.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10011 + 10012.

It is an arithmetic number, because the mean of its divisors is an integer number (10012).

2²⁰⁰²³ is an apocalyptic number.

20023 is a deficient number, since it is larger than the sum of its proper divisors (1).

20023 is an equidigital number, since it uses as much as digits as its factorization.

20023 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12, while the sum is 7.

The square root of 20023 is about 141.5026501519. The cubic root of 20023 is about 27.1545774473.

Adding to 20023 its reverse (32002), we get a palindrome (52025).

It can be divided in two parts, 2002 and 3, that multiplied together give a palindrome (6006).

The spelling of 20023 in words is "twenty thousand, twenty-three", and thus it is an iban number.