21112222 has 16 divisors (see below), whose sum is σ = 32457744. Its totient is φ = 10296000.

The previous prime is 21112207. The next prime is 21112241. The reversal of 21112222 is 22221112.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 15322 + ... + 16642.

It is an arithmetic number, because the mean of its divisors is an integer number (2028609).

Almost surely, 2^21112222 is an apocalyptic number.

21112222 is a deficient number, since it is larger than the sum of its proper divisors (11345522).

21112222 is a wasteful number, since it uses less digits than its factorization.

21112222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1515.

The product of its digits is 32, while the sum is 13.

The square root of 21112222 is about 4594.8038042989. The cubic root of 21112222 is about 276.3829924129.

Adding to 21112222 its reverse (22221112), we get a palindrome (43333334).

It can be divided in two parts, 21112 and 222, that multiplied together give a palindrome (4686864).

The spelling of 21112222 in words is "twenty-one million, one hundred twelve thousand, two hundred twenty-two".