20231 has 2 divisors, whose sum is σ = 20232.
Its totient is φ = 20230.
The previous prime is 20219. The next prime is 20233. The reversal of 20231 is 13202.
It is a strong prime.
It is a cyclic number.
It is not a de Polignac number, because 20231 - 210 = 19207 is a prime.
It is a super-2 number, since 2×202312 = 818586722, which contains 22 as substring.
Together with 20233, it forms a pair of twin primes.
It is a Chen prime.
It is a plaindrome in base 6.
It is a nialpdrome in base 14.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (20233) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10115 + 10116.
It is an arithmetic number, because the mean of its divisors is an integer number (10116).
220231 is an apocalyptic number.
20231 is a deficient number, since it is larger than the sum of its proper divisors (1).
20231 is an equidigital number, since it uses as much as digits as its factorization.
20231 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 12, while the sum is 8.
The square root of 20231 is about 142.2357198456.
The cubic root of 20231 is about 27.2482814616.
Adding to 20231 its reverse (13202), we get a palindrome (33433).
The spelling of 20231 in words is "twenty thousand, two hundred thirty-one".