21442244 has 6 divisors (see below), whose sum is σ = 37523934. Its totient is φ = 10721120.

The previous prime is 21442243. The next prime is 21442261. The reversal of 21442244 is 44224412.

It can be written as a sum of positive squares in only one way, i.e., 15132100 + 6310144 = 3890^2 + 2512^2 .

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21442243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2680277 + ... + 2680284.

It is an arithmetic number, because the mean of its divisors is an integer number (6253989).

Almost surely, 2^21442244 is an apocalyptic number.

It is an amenable number.

21442244 is a deficient number, since it is larger than the sum of its proper divisors (16081690).

21442244 is a wasteful number, since it uses less digits than its factorization.

21442244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5360565 (or 5360563 counting only the distinct ones).

The product of its digits is 2048, while the sum is 23.

The square root of 21442244 is about 4630.5770698694. The cubic root of 21442244 is about 277.8156740949.

Adding to 21442244 its reverse (44224412), we get a palindrome (65666656).

The spelling of 21442244 in words is "twenty-one million, four hundred forty-two thousand, two hundred forty-four".