21323303 has 4 divisors (see below), whose sum is σ = 21359040. Its totient is φ = 21287568.

The previous prime is 21323297. The next prime is 21323311. The reversal of 21323303 is 30332312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21323303 - 2¹⁶ = 21257767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323503) 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, 16958 + ... + 18171.

It is an arithmetic number, because the mean of its divisors is an integer number (5339760).

Almost surely, 2^21323303 is an apocalyptic number.

21323303 is a deficient number, since it is larger than the sum of its proper divisors (35737).

21323303 is an equidigital number, since it uses as much as digits as its factorization.

21323303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35736.

The product of its (nonzero) digits is 324, while the sum is 17.

The square root of 21323303 is about 4617.7162104226. The cubic root of 21323303 is about 277.3010363968.

Adding to 21323303 its reverse (30332312), we get a palindrome (51655615).

Subtracting 21323303 from its reverse (30332312), we obtain a palindrome (9009009).

The spelling of 21323303 in words is "twenty-one million, three hundred twenty-three thousand, three hundred three".