21133223 has 4 divisors (see below), whose sum is σ = 21182688. Its totient is φ = 21083760.

The previous prime is 21133219. The next prime is 21133237. The reversal of 21133223 is 32233112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21133223 - 2² = 21133219 is a prime.

It is a super-2 number, since 2×21133223² = 893226228735458, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24086 + ... + 24947.

It is an arithmetic number, because the mean of its divisors is an integer number (5295672).

Almost surely, 2^21133223 is an apocalyptic number.

21133223 is a deficient number, since it is larger than the sum of its proper divisors (49465).

21133223 is an equidigital number, since it uses as much as digits as its factorization.

21133223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49464.

The product of its digits is 216, while the sum is 17.

The square root of 21133223 is about 4597.0885351492. The cubic root of 21133223 is about 276.4746043665.

Adding to 21133223 its reverse (32233112), we get a palindrome (53366335).

The spelling of 21133223 in words is "twenty-one million, one hundred thirty-three thousand, two hundred twenty-three".