21095 has 4 divisors (see below), whose sum is σ = 25320. Its totient is φ = 16872.

The previous prime is 21089. The next prime is 21101. The reversal of 21095 is 59012.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21089) and next prime (21101).

It is a cyclic number.

It is not a de Polignac number, because 21095 - 2⁶ = 21031 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 21095.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2105 + ... + 2114.

It is an arithmetic number, because the mean of its divisors is an integer number (6330).

2²¹⁰⁹⁵ is an apocalyptic number.

21095 is a deficient number, since it is larger than the sum of its proper divisors (4225).

21095 is an equidigital number, since it uses as much as digits as its factorization.

21095 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4224.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 21095 is about 145.2411787339. The cubic root of 21095 is about 27.6307820115.

Adding to 21095 its sum of digits (17), we get a palindrome (21112).

The spelling of 21095 in words is "twenty-one thousand, ninety-five".