21338 has 8 divisors (see below), whose sum is σ = 32832. Its totient is φ = 10396.

The previous prime is 21323. The next prime is 21341. The reversal of 21338 is 83312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20 + ... + 207.

It is an arithmetic number, because the mean of its divisors is an integer number (4104).

2²¹³³⁸ is an apocalyptic number.

21338 is a deficient number, since it is larger than the sum of its proper divisors (11494).

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 product of its digits is 144, while the sum is 17.

The square root of 21338 is about 146.0753230358. The cubic root of 21338 is about 27.7364731303.

Subtracting from 21338 its sum of digits (17), we obtain a triangular number (21321 = T₂₀₆).

The spelling of 21338 in words is "twenty-one thousand, three hundred thirty-eight".