21342 has 8 divisors (see below), whose sum is σ = 42696. Its totient is φ = 7112.

The previous prime is 21341. The next prime is 21347. The reversal of 21342 is 24312.

It is a sphenic number, since it is the product of 3 distinct primes.

21342 is an admirable number.

It is an Ulam 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, 1773 + ... + 1784.

It is an arithmetic number, because the mean of its divisors is an integer number (5337).

2²¹³⁴² is an apocalyptic number.

21342 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21348).

21342 is a wasteful number, since it uses less digits than its factorization.

21342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3562.

The product of its digits is 48, while the sum is 12.

The square root of 21342 is about 146.0890139607. The cubic root of 21342 is about 27.7382061725.

Adding to 21342 its reverse (24312), we get a palindrome (45654).

It can be divided in two parts, 21 and 342, that added together give a palindrome (363).

The spelling of 21342 in words is "twenty-one thousand, three hundred forty-two", and thus it is an iban number.