21122222 has 16 divisors (see below), whose sum is σ = 35679744. Its totient is φ = 9291000.

The previous prime is 21122221. The next prime is 21122251. The reversal of 21122222 is 22222112.

It is a super-2 number, since 2×21122222² = 892296524434568, which contains 22 as substring.

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

21122222 is a modest number, since divided by 2222 gives 2112 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 21122197 and 21122206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122221) 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 7 ways as a sum of consecutive naturals, for example, 14804 + ... + 16167.

It is an arithmetic number, because the mean of its divisors is an integer number (2229984).

Almost surely, 2^21122222 is an apocalyptic number.

21122222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21122222 is a deficient number, since it is larger than the sum of its proper divisors (14557522).

21122222 is a wasteful number, since it uses less digits than its factorization.

21122222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31015.

The product of its digits is 64, while the sum is 14.

The square root of 21122222 is about 4595.8918612169. The cubic root of 21122222 is about 276.4266226487.

Adding to 21122222 its reverse (22222112), we get a palindrome (43344334).

It can be divided in two parts, 2112 and 2222, that added together give a palindrome (4334).

The spelling of 21122222 in words is "twenty-one million, one hundred twenty-two thousand, two hundred twenty-two".