21120220110 has 64 divisors (see below), whose sum is σ = 55455321600. Its totient is φ = 5105354880.

The previous prime is 21120220109. The next prime is 21120220117. The reversal of 21120220110 is 1102202112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120220117) 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 31 ways as a sum of consecutive naturals, for example, 23479 + ... + 206861.

It is an arithmetic number, because the mean of its divisors is an integer number (866489400).

Almost surely, 2^21120220110 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21120220110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27727660800).

21120220110 is an abundant number, since it is smaller than the sum of its proper divisors (34335101490).

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

21120220110 is a wasteful number, since it uses less digits than its factorization.

21120220110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183753.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21120220110 its reverse (1102202112), we get a palindrome (22222422222).

The spelling of 21120220110 in words is "twenty-one billion, one hundred twenty million, two hundred twenty thousand, one hundred ten".