20959 has 2 divisors, whose sum is σ = 20960. Its totient is φ = 20958.

The previous prime is 20947. The next prime is 20963. The reversal of 20959 is 95902.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20959 - 2¹¹ = 18911 is a prime.

20959 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10479 + 10480.

It is an arithmetic number, because the mean of its divisors is an integer number (10480).

2²⁰⁹⁵⁹ is an apocalyptic number.

20959 is a deficient number, since it is larger than the sum of its proper divisors (1).

20959 is an equidigital number, since it uses as much as digits as its factorization.

20959 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 810, while the sum is 25.

The square root of 20959 is about 144.7722349071. The cubic root of 20959 is about 27.5712751628.

It can be divided in two parts, 20 and 959, that added together give a palindrome (979).

The spelling of 20959 in words is "twenty thousand, nine hundred fifty-nine".