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.
221232 is an apocalyptic number.
It is an amenable number.
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 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).
The spelling of 21232 in words is "twenty-one thousand, two hundred thirty-two".