21233210 has 16 divisors (see below), whose sum is σ = 38313000. Its totient is φ = 8472576.

The previous prime is 21233197. The next prime is 21233213. The reversal of 21233210 is 1233212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 11826721 + 9406489 = 3439^2 + 3067^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21233213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2126 + ... + 6854.

It is a self-describing number.

Almost surely, 2^21233210 is an apocalyptic number.

21233210 is a deficient number, since it is larger than the sum of its proper divisors (17079790).

21233210 is a wasteful number, since it uses less digits than its factorization.

21233210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5185.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21233210 is about 4607.9507375839. The cubic root of 21233210 is about 276.9099439205.

Adding to 21233210 its reverse (1233212), we get a palindrome (22466422).

The spelling of 21233210 in words is "twenty-one million, two hundred thirty-three thousand, two hundred ten".