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