21442204 has 36 divisors (see below), whose sum is σ = 45071040. Its totient is φ = 8890560.

The previous prime is 21442163. The next prime is 21442229. The reversal of 21442204 is 40224412.

It is a super-2 number, since 2×21442204² = 919536224755232, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4312 + ... + 7840.

Almost surely, 2^21442204 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21442204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22535520).

21442204 is an abundant number, since it is smaller than the sum of its proper divisors (23628836).

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

21442204 is a wasteful number, since it uses less digits than its factorization.

21442204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3578 (or 3569 counting only the distinct ones).

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

The square root of 21442204 is about 4630.5727507513. The cubic root of 21442204 is about 277.8155013419.

Adding to 21442204 its reverse (40224412), we get a palindrome (61666616).

It can be divided in two parts, 21 and 442204, that added together give a square (442225 = 665²).

The spelling of 21442204 in words is "twenty-one million, four hundred forty-two thousand, two hundred four".