It is a semiprime because it is the product of two primes.
It is a self number, because there is not a number n which added to its sum of digits gives 21302.
It is a congruent number.
It is an unprimeable number.
221302 is an apocalyptic number.
21302 is a wasteful number, since it uses less digits than its factorization.
21302 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 10653.
The square root of 21302 is about 145.9520469195. The cubic root of 21302 is about 27.7208659959.
Adding to 21302 its reverse (20312), we get a palindrome (41614).
Subtracting from 21302 its reverse (20312), we obtain a triangular number (990 = T44).
The spelling of 21302 in words is "twenty-one thousand, three hundred two", and thus it is an iban number.