21110111122111 has 16 divisors (see below), whose sum is σ = 23289169144320. Its totient is φ = 18974401526080.

The previous prime is 21110111122103. The next prime is 21110111122123. The reversal of 21110111122111 is 11122111101112.

It is not a de Polignac number, because 21110111122111 - 2³ = 21110111122103 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110111122141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18766200 + ... + 19859266.

It is an arithmetic number, because the mean of its divisors is an integer number (1455573071520).

Almost surely, 2^{21110111122111} is an apocalyptic number.

21110111122111 is a deficient number, since it is larger than the sum of its proper divisors (2179058022209).

21110111122111 is a wasteful number, since it uses less digits than its factorization.

21110111122111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112894.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 21110111122111 its reverse (11122111101112), we get a palindrome (32232222223223).

The spelling of 21110111122111 in words is "twenty-one trillion, one hundred ten billion, one hundred eleven million, one hundred twenty-two thousand, one hundred eleven".