21238 has 16 divisors (see below), whose sum is σ = 38304. Its totient is φ = 8640.

The previous prime is 21227. The next prime is 21247. The reversal of 21238 is 83212.

It is a happy number.

21238 is nontrivially palindromic in base 13.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 498 + ... + 538.

It is an arithmetic number, because the mean of its divisors is an integer number (2394).

2²¹²³⁸ is an apocalyptic number.

21238 is a deficient number, since it is larger than the sum of its proper divisors (17066).

21238 is a wasteful number, since it uses less digits than its factorization.

21238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87.

The product of its digits is 96, while the sum is 16.

The square root of 21238 is about 145.7326318983. The cubic root of 21238 is about 27.6930765060.

The spelling of 21238 in words is "twenty-one thousand, two hundred thirty-eight".