Subtracting from 21338 its sum of digits (17), we obtain a triangular number (21321 = T206).
It is a sphenic number, since it is the product of 3 distinct primes.
It is a Curzon number.
It is an unprimeable number.
221338 is an apocalyptic number.
21338 is a wasteful number, since it uses less digits than its factorization.
21338 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 276.
The square root of 21338 is about 146.0753230358. The cubic root of 21338 is about 27.7364731303.
The spelling of 21338 in words is "twenty-one thousand, three hundred thirty-eight".