21224200 has 24 divisors (see below), whose sum is σ = 49346730. Its totient is φ = 8489600.

The previous prime is 21224191. The next prime is 21224207. The reversal of 21224200 is 242212.

It can be written as a sum of positive squares in 3 ways, for example, as 18992164 + 2232036 = 4358^2 + 1494^2 .

It is not an unprimeable number, because it can be changed into a prime (21224207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52861 + ... + 53260.

Almost surely, 2^21224200 is an apocalyptic number.

21224200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21224200 is an abundant number, since it is smaller than the sum of its proper divisors (28122530).

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

21224200 is a wasteful number, since it uses less digits than its factorization.

21224200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106137 (or 106128 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21224200 is about 4606.9729758270. The cubic root of 21224200 is about 276.8707708268.

Adding to 21224200 its reverse (242212), we get a palindrome (21466412).

The spelling of 21224200 in words is "twenty-one million, two hundred twenty-four thousand, two hundred".