21303204 has 24 divisors (see below), whose sum is σ = 53531520. Its totient is φ = 6554784.

The previous prime is 21303203. The next prime is 21303209. The reversal of 21303204 is 40230312.

It is not an unprimeable number, because it can be changed into a prime (21303203) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 68124 + ... + 68435.

It is an arithmetic number, because the mean of its divisors is an integer number (2230480).

Almost surely, 2^21303204 is an apocalyptic number.

It is an amenable number.

21303204 is an abundant number, since it is smaller than the sum of its proper divisors (32228316).

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

21303204 is a wasteful number, since it uses less digits than its factorization.

21303204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136579 (or 136577 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21303204 is about 4615.5394050967. The cubic root of 21303204 is about 277.2138825195.

Adding to 21303204 its reverse (40230312), we get a palindrome (61533516).

The spelling of 21303204 in words is "twenty-one million, three hundred three thousand, two hundred four".