21222844 has 12 divisors (see below), whose sum is σ = 37172968. Its totient is φ = 10602000.

The previous prime is 21222787. The next prime is 21222847. The reversal of 21222844 is 44822212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222847) 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, 6019 + ... + 8869.

Almost surely, 2^21222844 is an apocalyptic number.

It is an amenable number.

21222844 is a deficient number, since it is larger than the sum of its proper divisors (15950124).

21222844 is a wasteful number, since it uses less digits than its factorization.

21222844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4716 (or 4714 counting only the distinct ones).

The product of its digits is 2048, while the sum is 25.

The square root of 21222844 is about 4606.8258052590. The cubic root of 21222844 is about 276.8648743382.

The spelling of 21222844 in words is "twenty-one million, two hundred twenty-two thousand, eight hundred forty-four".