21111222112110 has 384 divisors, whose sum is σ = 64678477159296. Its totient is φ = 4729865011200.

The previous prime is 21111222112063. The next prime is 21111222112177. The reversal of 21111222112110 is 1121122211112.

It is a happy number.

21111222112110 is a `hidden beast` number, since 211 + 11 + 22 + 211 + 211 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 86260074 + ... + 86504466.

It is an arithmetic number, because the mean of its divisors is an integer number (168433534269).

Almost surely, 2^{21111222112110} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21111222112110, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32339238579648).

21111222112110 is an abundant number, since it is smaller than the sum of its proper divisors (43567255047186).

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

21111222112110 is a wasteful number, since it uses less digits than its factorization.

21111222112110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244580 (or 244577 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21111222112110 its reverse (1121122211112), we get a palindrome (22232344323222).

The spelling of 21111222112110 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, one hundred twelve thousand, one hundred ten".