21344 has 24 divisors (see below), whose sum is σ = 45360. Its totient is φ = 9856.

The previous prime is 21341. The next prime is 21347. The reversal of 21344 is 44312.

It is an interprime number because it is at equal distance from previous prime (21341) and next prime (21347).

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, 722 + ... + 750.

It is an arithmetic number, because the mean of its divisors is an integer number (1890).

2²¹³⁴⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22680).

21344 is an abundant number, since it is smaller than the sum of its proper divisors (24016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21344 is a wasteful number, since it uses less digits than its factorization.

21344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62 (or 54 counting only the distinct ones).

The product of its digits is 96, while the sum is 14.

The square root of 21344 is about 146.0958589420. The cubic root of 21344 is about 27.7390726123.

Adding to 21344 its reverse (44312), we get a palindrome (65656).

The spelling of 21344 in words is "twenty-one thousand, three hundred forty-four", and thus it is an iban number.