21320333 has 4 divisors (see below), whose sum is σ = 22247328. Its totient is φ = 20393340.

The previous prime is 21320323. The next prime is 21320401. The reversal of 21320333 is 33302312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21320333 - 2⁴ = 21320317 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320323) 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 3 ways as a sum of consecutive naturals, for example, 463463 + ... + 463508.

It is an arithmetic number, because the mean of its divisors is an integer number (5561832).

Almost surely, 2^21320333 is an apocalyptic number.

21320333 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21320333 is a deficient number, since it is larger than the sum of its proper divisors (926995).

21320333 is an equidigital number, since it uses as much as digits as its factorization.

21320333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 926994.

The product of its (nonzero) digits is 324, while the sum is 17.

The square root of 21320333 is about 4617.3946116831. The cubic root of 21320333 is about 277.2881612446.

Adding to 21320333 its reverse (33302312), we get a palindrome (54622645).

The spelling of 21320333 in words is "twenty-one million, three hundred twenty thousand, three hundred thirty-three".