20929 has 2 divisors, whose sum is σ = 20930. Its totient is φ = 20928.

The previous prime is 20921. The next prime is 20939. The reversal of 20929 is 92902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18225 + 2704 = 135^2 + 52^2 .

It is a cyclic number.

It is not a de Polignac number, because 20929 - 2³ = 20921 is a prime.

It is a Chen prime.

It is a plaindrome in base 14.

It is not a weakly prime, because it can be changed into another prime (20921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10464 + 10465.

It is an arithmetic number, because the mean of its divisors is an integer number (10465).

2²⁰⁹²⁹ is an apocalyptic number.

It is an amenable number.

20929 is a deficient number, since it is larger than the sum of its proper divisors (1).

20929 is an equidigital number, since it uses as much as digits as its factorization.

20929 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 20929 is about 144.6685867768. The cubic root of 20929 is about 27.5581140194.

It can be divided in two parts, 20 and 929, that added together give a palindrome (949).

The spelling of 20929 in words is "twenty thousand, nine hundred twenty-nine".