21120111222 has 48 divisors (see below), whose sum is σ = 49277617200. Its totient is φ = 6016997952.

The previous prime is 21120111209. The next prime is 21120111227. The reversal of 21120111222 is 22211102112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120111227) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 313 + ... + 205524.

It is an arithmetic number, because the mean of its divisors is an integer number (1026617025).

Almost surely, 2^21120111222 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21120111222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24638808600).

21120111222 is an abundant number, since it is smaller than the sum of its proper divisors (28157505978).

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

21120111222 is a wasteful number, since it uses less digits than its factorization.

21120111222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206205 (or 206198 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21120111222 its reverse (22211102112), we get a palindrome (43331213334).

The spelling of 21120111222 in words is "twenty-one billion, one hundred twenty million, one hundred eleven thousand, two hundred twenty-two".