21327 has 4 divisors (see below), whose sum is σ = 28440. Its totient is φ = 14216.

The previous prime is 21323. The next prime is 21341. The reversal of 21327 is 72312.

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

It is a cyclic number.

It is not a de Polignac number, because 21327 - 2² = 21323 is a prime.

It is a D-number.

21327 is a lucky number.

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 in 3 ways as a sum of consecutive naturals, for example, 3552 + ... + 3557.

It is an arithmetic number, because the mean of its divisors is an integer number (7110).

2²¹³²⁷ is an apocalyptic number.

21327 is a deficient number, since it is larger than the sum of its proper divisors (7113).

21327 is an equidigital number, since it uses as much as digits as its factorization.

21327 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7112.

The product of its digits is 84, while the sum is 15.

The square root of 21327 is about 146.0376663741. The cubic root of 21327 is about 27.7317061473.

Subtracting from 21327 its sum of digits (15), we obtain a palindrome (21312).

Adding to 21327 its reverse (72312), we get a palindrome (93639).

The spelling of 21327 in words is "twenty-one thousand, three hundred twenty-seven", and thus it is an iban number.