21812204 has 12 divisors (see below), whose sum is σ = 38401104. Its totient is φ = 10840464.

The previous prime is 21812201. The next prime is 21812213. The reversal of 21812204 is 40221812.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21812201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15659 + ... + 16994.

It is an arithmetic number, because the mean of its divisors is an integer number (3200092).

Almost surely, 2^21812204 is an apocalyptic number.

It is an amenable number.

21812204 is a deficient number, since it is larger than the sum of its proper divisors (16588900).

21812204 is a wasteful number, since it uses less digits than its factorization.

21812204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32824 (or 32822 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 21812204 is about 4670.3537339264. The cubic root of 21812204 is about 279.4043630668.

The spelling of 21812204 in words is "twenty-one million, eight hundred twelve thousand, two hundred four".