21244204 has 24 divisors (see below), whose sum is σ = 39435200. Its totient is φ = 9985680.

The previous prime is 21244199. The next prime is 21244213. The reversal of 21244204 is 40244212.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9559 + ... + 11569.

Almost surely, 2^21244204 is an apocalyptic number.

It is an amenable number.

21244204 is a deficient number, since it is larger than the sum of its proper divisors (18190996).

21244204 is a wasteful number, since it uses less digits than its factorization.

21244204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2173 (or 2171 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 21244204 is about 4609.1435213063. The cubic root of 21244204 is about 276.9577279131.

Adding to 21244204 its reverse (40244212), we get a palindrome (61488416).

It can be divided in two parts, 2124 and 4204, that added together give a triangular number (6328 = T₁₁₂).

The spelling of 21244204 in words is "twenty-one million, two hundred forty-four thousand, two hundred four".