21330236 has 48 divisors (see below), whose sum is σ = 41247360. Its totient is φ = 9616320.

The previous prime is 21330163. The next prime is 21330251. The reversal of 21330236 is 63203312.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 199295 + ... + 199401.

It is an arithmetic number, because the mean of its divisors is an integer number (859320).

Almost surely, 2^21330236 is an apocalyptic number.

It is an amenable number.

21330236 is a deficient number, since it is larger than the sum of its proper divisors (19917124).

21330236 is a wasteful number, since it uses less digits than its factorization.

21330236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234 (or 232 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

The square root of 21330236 is about 4618.4668451771. The cubic root of 21330236 is about 277.3310867719.

Adding to 21330236 its reverse (63203312), we get a palindrome (84533548).

The spelling of 21330236 in words is "twenty-one million, three hundred thirty thousand, two hundred thirty-six".