21272444 has 12 divisors (see below), whose sum is σ = 38092824. Its totient is φ = 10388784.

The previous prime is 21272443. The next prime is 21272453. The reversal of 21272444 is 44427212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61667 + ... + 62010.

It is an arithmetic number, because the mean of its divisors is an integer number (3174402).

Almost surely, 2^21272444 is an apocalyptic number.

It is an amenable number.

21272444 is a deficient number, since it is larger than the sum of its proper divisors (16820380).

21272444 is a wasteful number, since it uses less digits than its factorization.

21272444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123724 (or 123722 counting only the distinct ones).

The product of its digits is 3584, while the sum is 26.

The square root of 21272444 is about 4612.2059797888. The cubic root of 21272444 is about 277.0803938910.

Adding to 21272444 its reverse (44427212), we get a palindrome (65699656).

The spelling of 21272444 in words is "twenty-one million, two hundred seventy-two thousand, four hundred forty-four".