21112121221110 has 24 divisors (see below), whose sum is σ = 54891515175120. Its totient is φ = 5629898992272.

The previous prime is 21112121221069. The next prime is 21112121221129. The reversal of 21112121221110 is 1112212121112.

It is a happy number.

21112121221110 is a `hidden beast` number, since 211 + 1 + 2 + 121 + 221 + 110 = 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 11 ways as a sum of consecutive naturals, for example, 117289562250 + ... + 117289562429.

It is an arithmetic number, because the mean of its divisors is an integer number (2287146465630).

Almost surely, 2^{21112121221110} is an apocalyptic number.

21112121221110 is an abundant number, since it is smaller than the sum of its proper divisors (33779393954010).

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

21112121221110 is a wasteful number, since it uses less digits than its factorization.

21112121221110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 234579124692 (or 234579124689 counting only the distinct ones).

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

Adding to 21112121221110 its reverse (1112212121112), we get a palindrome (22224333342222).

The spelling of 21112121221110 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, two hundred twenty-one thousand, one hundred ten".