21359 has 8 divisors (see below), whose sum is σ = 24192. Its totient is φ = 18720.

The previous prime is 21347. The next prime is 21377. The reversal of 21359 is 95312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21359 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21359.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 377 + ... + 429.

It is an arithmetic number, because the mean of its divisors is an integer number (3024).

2²¹³⁵⁹ is an apocalyptic number.

21359 is a deficient number, since it is larger than the sum of its proper divisors (2833).

21359 is a wasteful number, since it uses less digits than its factorization.

21359 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97.

The product of its digits is 270, while the sum is 20.

The square root of 21359 is about 146.1471860831. The cubic root of 21359 is about 27.7455691868.

It can be divided in two parts, 213 and 59, that added together give a palindrome (272).

The spelling of 21359 in words is "twenty-one thousand, three hundred fifty-nine".