21110223 has 4 divisors (see below), whose sum is σ = 28146968. Its totient is φ = 14073480.

The previous prime is 21110189. The next prime is 21110227. The reversal of 21110223 is 32201112.

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

It is not a de Polignac number, because 21110223 - 2¹⁶ = 21044687 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21110199 and 21110208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110227) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3518368 + ... + 3518373.

It is an arithmetic number, because the mean of its divisors is an integer number (7036742).

Almost surely, 2^21110223 is an apocalyptic number.

21110223 is a deficient number, since it is larger than the sum of its proper divisors (7036745).

21110223 is an equidigital number, since it uses as much as digits as its factorization.

21110223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7036744.

The product of its (nonzero) digits is 24, while the sum is 12.

The square root of 21110223 is about 4594.5862708192. The cubic root of 21110223 is about 276.3742690766.

Adding to 21110223 its reverse (32201112), we get a palindrome (53311335).

The spelling of 21110223 in words is "twenty-one million, one hundred ten thousand, two hundred twenty-three".