21323304 has 64 divisors (see below), whose sum is σ = 62726400. Its totient is φ = 6688512.

The previous prime is 21323297. The next prime is 21323311. The reversal of 21323304 is 40332312.

It is an interprime number because it is at equal distance from previous prime (21323297) and next prime (21323311).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 769 + ... + 6575.

It is an arithmetic number, because the mean of its divisors is an integer number (980100).

Almost surely, 2^21323304 is an apocalyptic number.

21323304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31363200).

21323304 is an abundant number, since it is smaller than the sum of its proper divisors (41403096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21323304 is a wasteful number, since it uses less digits than its factorization.

21323304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5839 (or 5829 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 21323304 is about 4617.7163187013. The cubic root of 21323304 is about 277.3010407317.

Adding to 21323304 its reverse (40332312), we get a palindrome (61655616).

The spelling of 21323304 in words is "twenty-one million, three hundred twenty-three thousand, three hundred four".