21224204 has 6 divisors (see below), whose sum is σ = 37142364. Its totient is φ = 10612100.

The previous prime is 21224191. The next prime is 21224207. The reversal of 21224204 is 40242212.

It is a happy number.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2653022 + ... + 2653029.

It is an arithmetic number, because the mean of its divisors is an integer number (6190394).

Almost surely, 2^21224204 is an apocalyptic number.

It is an amenable number.

21224204 is a deficient number, since it is larger than the sum of its proper divisors (15918160).

21224204 is a wasteful number, since it uses less digits than its factorization.

21224204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5306055 (or 5306053 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 21224204 is about 4606.9734099515. The cubic root of 21224204 is about 276.8707882202.

Adding to 21224204 its reverse (40242212), we get a palindrome (61466416).

The spelling of 21224204 in words is "twenty-one million, two hundred twenty-four thousand, two hundred four".