21202224 has 20 divisors (see below), whose sum is σ = 54772536. Its totient is φ = 7067392.

The previous prime is 21202211. The next prime is 21202261. The reversal of 21202224 is 42220212.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220809 + ... + 220904.

Almost surely, 2^21202224 is an apocalyptic number.

21202224 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21202224 is an abundant number, since it is smaller than the sum of its proper divisors (33570312).

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

21202224 is a wasteful number, since it uses less digits than its factorization.

21202224 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 441724 (or 441718 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 21202224 is about 4604.5872779219. The cubic root of 21202224 is about 276.7751784797.

Adding to 21202224 its reverse (42220212), we get a palindrome (63422436).

The spelling of 21202224 in words is "twenty-one million, two hundred two thousand, two hundred twenty-four".