21022244 has 6 divisors (see below), whose sum is σ = 36788934. Its totient is φ = 10511120.

The previous prime is 21022223. The next prime is 21022249. The reversal of 21022244 is 44222012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12390400 + 8631844 = 3520^2 + 2938^2 .

It is not an unprimeable number, because it can be changed into a prime (21022249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2627777 + ... + 2627784.

It is an arithmetic number, because the mean of its divisors is an integer number (6131489).

Almost surely, 2^21022244 is an apocalyptic number.

It is an amenable number.

21022244 is a deficient number, since it is larger than the sum of its proper divisors (15766690).

21022244 is a wasteful number, since it uses less digits than its factorization.

21022244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5255565 (or 5255563 counting only the distinct ones).

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

The square root of 21022244 is about 4585.0020719734. The cubic root of 21022244 is about 275.9897951838.

Adding to 21022244 its reverse (44222012), we get a palindrome (65244256).

The spelling of 21022244 in words is "twenty-one million, twenty-two thousand, two hundred forty-four".