21326 has 4 divisors (see below), whose sum is σ = 31992. Its totient is φ = 10662.

The previous prime is 21323. The next prime is 21341. The reversal of 21326 is 62312.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21326.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5330 + ... + 5333.

It is an arithmetic number, because the mean of its divisors is an integer number (7998).

2²¹³²⁶ is an apocalyptic number.

21326 is a deficient number, since it is larger than the sum of its proper divisors (10666).

21326 is a wasteful number, since it uses less digits than its factorization.

21326 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10665.

The product of its digits is 72, while the sum is 14.

The square root of 21326 is about 146.0342425598. The cubic root of 21326 is about 27.7312727040.

Subtracting from 21326 its sum of digits (14), we obtain a palindrome (21312).

Adding to 21326 its reverse (62312), we get a palindrome (83638).

The spelling of 21326 in words is "twenty-one thousand, three hundred twenty-six".