21422444 has 12 divisors (see below), whose sum is σ = 37656024. Its totient is φ = 10663584.

The previous prime is 21422419. The next prime is 21422449. The reversal of 21422444 is 44422412.

It is a super-2 number, since 2×21422444² = 917842213866272, which contains 22 as substring.

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 (21422449) 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, 10889 + ... + 12704.

It is an arithmetic number, because the mean of its divisors is an integer number (3138002).

Almost surely, 2^21422444 is an apocalyptic number.

It is an amenable number.

21422444 is a deficient number, since it is larger than the sum of its proper divisors (16233580).

21422444 is a wasteful number, since it uses less digits than its factorization.

21422444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23824 (or 23822 counting only the distinct ones).

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

The square root of 21422444 is about 4628.4386136147. The cubic root of 21422444 is about 277.7301350943.

Adding to 21422444 its reverse (44422412), we get a palindrome (65844856).

The spelling of 21422444 in words is "twenty-one million, four hundred twenty-two thousand, four hundred forty-four".