21242223 has 32 divisors (see below), whose sum is σ = 33331200. Its totient is φ = 13348800.

The previous prime is 21242203. The next prime is 21242237. The reversal of 21242223 is 32224212.

It is not a de Polignac number, because 21242223 - 2⁵ = 21242191 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21242196 and 21242205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21242203) 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 31 ways as a sum of consecutive naturals, for example, 34008 + ... + 34626.

It is an arithmetic number, because the mean of its divisors is an integer number (1041600).

Almost surely, 2^21242223 is an apocalyptic number.

21242223 is a deficient number, since it is larger than the sum of its proper divisors (12088977).

21242223 is a wasteful number, since it uses less digits than its factorization.

21242223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700 (or 694 counting only the distinct ones).

The product of its digits is 384, while the sum is 18.

The square root of 21242223 is about 4608.9286173687. The cubic root of 21242223 is about 276.9491189719.

Adding to 21242223 its reverse (32224212), we get a palindrome (53466435).

The spelling of 21242223 in words is "twenty-one million, two hundred forty-two thousand, two hundred twenty-three".