21220111110 has 192 divisors, whose sum is σ = 59629872384. Its totient is φ = 4791552000.

The previous prime is 21220111109. The next prime is 21220111139. The reversal of 21220111110 is 1111102212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9631269 + ... + 9633471.

It is an arithmetic number, because the mean of its divisors is an integer number (310572252).

Almost surely, 2^21220111110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21220111110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29814936192).

21220111110 is an abundant number, since it is smaller than the sum of its proper divisors (38409761274).

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

21220111110 is a wasteful number, since it uses less digits than its factorization.

21220111110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2359 (or 2342 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21220111110 its reverse (1111102212), we get a palindrome (22331213322).

The spelling of 21220111110 in words is "twenty-one billion, two hundred twenty million, one hundred eleven thousand, one hundred ten".