21234304 has 64 divisors (see below), whose sum is σ = 52093440. Its totient is φ = 8395776.

The previous prime is 21234299. The next prime is 21234307. The reversal of 21234304 is 40343212.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (21234307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10737 + ... + 12559.

It is an arithmetic number, because the mean of its divisors is an integer number (813960).

Almost surely, 2^21234304 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21234304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26046720).

21234304 is an abundant number, since it is smaller than the sum of its proper divisors (30859136).

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

21234304 is a wasteful number, since it uses less digits than its factorization.

21234304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1857 (or 1845 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 21234304 is about 4608.0694439212. The cubic root of 21234304 is about 276.9146995883.

Adding to 21234304 its reverse (40343212), we get a palindrome (61577516).

The spelling of 21234304 in words is "twenty-one million, two hundred thirty-four thousand, three hundred four".