21444321 has 8 divisors (see below), whose sum is σ = 28678624. Its totient is φ = 14253120.

The previous prime is 21444299. The next prime is 21444323. The reversal of 21444321 is 12344412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21444321 - 2⁵ = 21444289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21444323) 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 7 ways as a sum of consecutive naturals, for example, 9595 + ... + 11616.

It is an arithmetic number, because the mean of its divisors is an integer number (3584828).

Almost surely, 2^21444321 is an apocalyptic number.

It is an amenable number.

21444321 is a deficient number, since it is larger than the sum of its proper divisors (7234303).

21444321 is a wasteful number, since it uses less digits than its factorization.

21444321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21551.

The product of its digits is 768, while the sum is 21.

The square root of 21444321 is about 4630.8013345424. The cubic root of 21444321 is about 277.8246439975.

Adding to 21444321 its reverse (12344412), we get a palindrome (33788733).

Subtracting from 21444321 its reverse (12344412), we obtain a palindrome (9099909).

The spelling of 21444321 in words is "twenty-one million, four hundred forty-four thousand, three hundred twenty-one".