21184228 has 24 divisors (see below), whose sum is σ = 40084352. Its totient is φ = 9738144.

The previous prime is 21184217. The next prime is 21184277. The reversal of 21184228 is 82248112.

It is a junction number, because it is equal to n+sod(n) for n = 21184196 and 21184205.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15301 + ... + 16627.

Almost surely, 2^21184228 is an apocalyptic number.

It is an amenable number.

21184228 is a deficient number, since it is larger than the sum of its proper divisors (18900124).

21184228 is a wasteful number, since it uses less digits than its factorization.

21184228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1651 (or 1649 counting only the distinct ones).

The product of its digits is 2048, while the sum is 28.

The square root of 21184228 is about 4602.6327248652. The cubic root of 21184228 is about 276.6968493385.

It can be divided in two parts, 21184 and 228, that added together give a palindrome (21412).

The spelling of 21184228 in words is "twenty-one million, one hundred eighty-four thousand, two hundred twenty-eight".