21135 is digitally balanced in base 4 and base 6, because in such bases it contains all the possibile digits an equal number of times.
It is a sphenic number, since it is the product of 3 distinct primes.
It is a cyclic number.
21135 is strictly pandigital in base 6.
It is a self number, because there is not a number n which added to its sum of digits gives 21135.
It is a congruent number.
221135 is an apocalyptic number.
21135 is a wasteful number, since it uses less digits than its factorization.
21135 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1417.
The square root of 21135 is about 145.3788155131. The cubic root of 21135 is about 27.6482353328.
Adding to 21135 its reverse (53112), we get a palindrome (74247).
The spelling of 21135 in words is "twenty-one thousand, one hundred thirty-five".