21633232 has 20 divisors (see below), whose sum is σ = 42085476. Its totient is φ = 10772480.

The previous prime is 21633221. The next prime is 21633239. The reversal of 21633232 is 23233612.

It can be written as a sum of positive squares in 2 ways, for example, as 19395216 + 2238016 = 4404^2 + 1496^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633239) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1482 + ... + 6742.

Almost surely, 2^21633232 is an apocalyptic number.

It is an amenable number.

21633232 is a deficient number, since it is larger than the sum of its proper divisors (20452244).

21633232 is a wasteful number, since it uses less digits than its factorization.

21633232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5526 (or 5520 counting only the distinct ones).

The product of its digits is 1296, while the sum is 22.

The square root of 21633232 is about 4651.1538353402. The cubic root of 21633232 is about 278.6380802413.

Adding to 21633232 its reverse (23233612), we get a palindrome (44866844).

The spelling of 21633232 in words is "twenty-one million, six hundred thirty-three thousand, two hundred thirty-two".