21125224 has 64 divisors (see below), whose sum is σ = 44323200. Its totient is φ = 9402624.

The previous prime is 21125219. The next prime is 21125227. The reversal of 21125224 is 42252112.

It is not an unprimeable number, because it can be changed into a prime (21125227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 197379 + ... + 197485.

It is an arithmetic number, because the mean of its divisors is an integer number (692550).

Almost surely, 2^21125224 is an apocalyptic number.

It is an amenable number.

21125224 is an abundant number, since it is smaller than the sum of its proper divisors (23197976).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21125224 is a wasteful number, since it uses less digits than its factorization.

21125224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 198 counting only the distinct ones).

The product of its digits is 320, while the sum is 19.

The square root of 21125224 is about 4596.2184456355. The cubic root of 21125224 is about 276.4397177579.

Adding to 21125224 its reverse (42252112), we get a palindrome (63377336).

The spelling of 21125224 in words is "twenty-one million, one hundred twenty-five thousand, two hundred twenty-four".