21330323 has 4 divisors (see below), whose sum is σ = 24377520. Its totient is φ = 18283128.

The previous prime is 21330313. The next prime is 21330347. The reversal of 21330323 is 32303312.

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 21330323 - 2⁶ = 21330259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21330313) 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, 1523588 + ... + 1523601.

It is an arithmetic number, because the mean of its divisors is an integer number (6094380).

Almost surely, 2^21330323 is an apocalyptic number.

21330323 is a deficient number, since it is larger than the sum of its proper divisors (3047197).

21330323 is an equidigital number, since it uses as much as digits as its factorization.

21330323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3047196.

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

The square root of 21330323 is about 4618.4762638775. The cubic root of 21330323 is about 277.3314638231.

Adding to 21330323 its reverse (32303312), we get a palindrome (53633635).

The spelling of 21330323 in words is "twenty-one million, three hundred thirty thousand, three hundred twenty-three".