21222112220 has 24 divisors (see below), whose sum is σ = 44790396000. Its totient is φ = 8446185792.

The previous prime is 21222112189. The next prime is 21222112229. The reversal of 21222112220 is 2221122212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222112229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2662115 + ... + 2670074.

It is an arithmetic number, because the mean of its divisors is an integer number (1866266500).

Almost surely, 2^21222112220 is an apocalyptic number.

21222112220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222112220 is an abundant number, since it is smaller than the sum of its proper divisors (23568283780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21222112220 is a wasteful number, since it uses less digits than its factorization.

21222112220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5332397 (or 5332395 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21222112220 its reverse (2221122212), we get a palindrome (23443234432).

The spelling of 21222112220 in words is "twenty-one billion, two hundred twenty-two million, one hundred twelve thousand, two hundred twenty".