20983 has 2 divisors, whose sum is σ = 20984. Its totient is φ = 20982.

The previous prime is 20981. The next prime is 21001. The reversal of 20983 is 38902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20983 - 2¹ = 20981 is a prime.

Together with 20981, it forms a pair of twin primes.

It is a nialpdrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10491 + 10492.

It is an arithmetic number, because the mean of its divisors is an integer number (10492).

2²⁰⁹⁸³ is an apocalyptic number.

20983 is a deficient number, since it is larger than the sum of its proper divisors (1).

20983 is an equidigital number, since it uses as much as digits as its factorization.

20983 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 20983 is about 144.8551000138. The cubic root of 20983 is about 27.5817950380.

It can be divided in two parts, 209 and 83, that added together give a palindrome (292).

The spelling of 20983 in words is "twenty thousand, nine hundred eighty-three".