21343 has 4 divisors (see below), whose sum is σ = 24400. Its totient is φ = 18288.

The previous prime is 21341. The next prime is 21347. The reversal of 21343 is 34312.

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 21343 - 2¹ = 21341 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21341) 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, 1518 + ... + 1531.

It is an arithmetic number, because the mean of its divisors is an integer number (6100).

2²¹³⁴³ is an apocalyptic number.

21343 is a deficient number, since it is larger than the sum of its proper divisors (3057).

21343 is an equidigital number, since it uses as much as digits as its factorization.

21343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3056.

The product of its digits is 72, while the sum is 13.

The square root of 21343 is about 146.0924364914. The cubic root of 21343 is about 27.7386393992.

Adding to 21343 its reverse (34312), we get a palindrome (55655).

It can be divided in two parts, 213 and 43, that added together give a 8-th power (256 = 2⁸).

The spelling of 21343 in words is "twenty-one thousand, three hundred forty-three", and thus it is an iban number.