21112221100110 has 128 divisors (see below), whose sum is σ = 61383595613184. Its totient is φ = 4536644474880.

The previous prime is 21112221100109. The next prime is 21112221100163. The reversal of 21112221100110 is 1100112221112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21112221100110.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 196381 + ... + 6501000.

It is an arithmetic number, because the mean of its divisors is an integer number (479559340728).

Almost surely, 2^{21112221100110} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21112221100110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30691797806592).

21112221100110 is an abundant number, since it is smaller than the sum of its proper divisors (40271374513074).

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

21112221100110 is a wasteful number, since it uses less digits than its factorization.

21112221100110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6698298.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21112221100110 its reverse (1100112221112), we get a palindrome (22212333321222).

The spelling of 21112221100110 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty-one million, one hundred thousand, one hundred ten".