21159 has 6 divisors (see below), whose sum is σ = 30576. Its totient is φ = 14100.

The previous prime is 21157. The next prime is 21163. The reversal of 21159 is 95112.

It is not a de Polignac number, because 21159 - 2¹ = 21157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21157) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1167 + ... + 1184.

It is an arithmetic number, because the mean of its divisors is an integer number (5096).

2²¹¹⁵⁹ is an apocalyptic number.

21159 is a deficient number, since it is larger than the sum of its proper divisors (9417).

21159 is a wasteful number, since it uses less digits than its factorization.

21159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2357 (or 2354 counting only the distinct ones).

The product of its digits is 90, while the sum is 18.

The square root of 21159 is about 145.4613350688. The cubic root of 21159 is about 27.6586967576.

The spelling of 21159 in words is "twenty-one thousand, one hundred fifty-nine".