It is a sphenic number, since it is the product of 3 distinct primes.
It is a Duffinian number.
It is a plaindrome in base 14.
It is a nialpdrome in base 13.
It is a congruent number.
It is an unprimeable number.
221335 is an apocalyptic number.
21335 is a wasteful number, since it uses less digits than its factorization.
21335 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 273.
The square root of 21335 is about 146.0650539999. The cubic root of 21335 is about 27.7351732065.
Subtracting from 21335 its sum of digits (14), we obtain a triangular number (21321 = T206).
Adding to 21335 its reverse (53312), we get a palindrome (74647).
The spelling of 21335 in words is "twenty-one thousand, three hundred thirty-five".