21232 has 10 divisors (see below), whose sum is σ = 41168. Its totient is φ = 10608.

The previous prime is 21227. The next prime is 21247. The reversal of 21232 is 23212.

21232 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.

It is an Ulam number.

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

It is a nialpdrome in base 9 and base 13.

It is a congruent number.

It is an unprimeable number.

21232 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 648 + ... + 679.

2²¹²³² is an apocalyptic number.

It is an amenable number.

21232 is a deficient number, since it is larger than the sum of its proper divisors (19936).

21232 is a wasteful number, since it uses less digits than its factorization.

21232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1335 (or 1329 counting only the distinct ones).

The product of its digits is 24, while the sum is 10.

The square root of 21232 is about 145.7120448007. The cubic root of 21232 is about 27.6904683805.

Adding to 21232 its reverse (23212), we get a palindrome (44444).

It can be divided in two parts, 21 and 232, that added together give a triangular number (253 = T₂₂).

The spelling of 21232 in words is "twenty-one thousand, two hundred thirty-two".