21310233 has 16 divisors (see below), whose sum is σ = 32919936. Its totient is φ = 12009600.

The previous prime is 21310207. The next prime is 21310243. The reversal of 21310233 is 33201312.

It is a de Polignac number, because none of the positive numbers 2^k-21310233 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21310243) 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 15 ways as a sum of consecutive naturals, for example, 5418 + ... + 8483.

It is an arithmetic number, because the mean of its divisors is an integer number (2057496).

Almost surely, 2^21310233 is an apocalyptic number.

It is an amenable number.

21310233 is a deficient number, since it is larger than the sum of its proper divisors (11609703).

21310233 is a wasteful number, since it uses less digits than its factorization.

21310233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13984.

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 21310233 is about 4616.3007917596. The cubic root of 21310233 is about 277.2443681077.

Adding to 21310233 its reverse (33201312), we get a palindrome (54511545).

The spelling of 21310233 in words is "twenty-one million, three hundred ten thousand, two hundred thirty-three".