21303344 has 20 divisors (see below), whose sum is σ = 41419224. Its totient is φ = 10614528.

The previous prime is 21303341. The next prime is 21303349. The reversal of 21303344 is 44330312.

It is not an unprimeable number, because it can be changed into a prime (21303341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2744 + ... + 7080.

Almost surely, 2^21303344 is an apocalyptic number.

It is an amenable number.

21303344 is a deficient number, since it is larger than the sum of its proper divisors (20115880).

21303344 is a wasteful number, since it uses less digits than its factorization.

21303344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4652 (or 4646 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 21303344 is about 4615.5545712298. The cubic root of 21303344 is about 277.2144897812.

Adding to 21303344 its reverse (44330312), we get a palindrome (65633656).

The spelling of 21303344 in words is "twenty-one million, three hundred three thousand, three hundred forty-four".