21633328 has 40 divisors (see below), whose sum is σ = 43309728. Its totient is φ = 10463232.

The previous prime is 21633289. The next prime is 21633329. The reversal of 21633328 is 82333612.

It is a junction number, because it is equal to n+sod(n) for n = 21633296 and 21633305.

It is not an unprimeable number, because it can be changed into a prime (21633329) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 82125 + ... + 82387.

Almost surely, 2^21633328 is an apocalyptic number.

It is an amenable number.

21633328 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

21633328 is a wasteful number, since it uses less digits than its factorization.

21633328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421 (or 415 counting only the distinct ones).

The product of its digits is 5184, while the sum is 28.

The square root of 21633328 is about 4651.1641553486. The cubic root of 21633328 is about 278.6384924038.

The spelling of 21633328 in words is "twenty-one million, six hundred thirty-three thousand, three hundred twenty-eight".