21595 has 8 divisors (see below), whose sum is σ = 29664. Its totient is φ = 14784.

The previous prime is 21589. The next prime is 21599. The reversal of 21595 is 59512.

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

It is not a de Polignac number, because 21595 - 2³ = 21587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21599) 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, 274 + ... + 343.

It is an arithmetic number, because the mean of its divisors is an integer number (3708).

2²¹⁵⁹⁵ is an apocalyptic number.

21595 is a deficient number, since it is larger than the sum of its proper divisors (8069).

21595 is an equidigital number, since it uses as much as digits as its factorization.

21595 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629.

The product of its digits is 450, while the sum is 22.

The square root of 21595 is about 146.9523732370. The cubic root of 21595 is about 27.8473839521.

It can be divided in two parts, 21 and 595, that added together give a palindrome (616).

The spelling of 21595 in words is "twenty-one thousand, five hundred ninety-five".