21111222112111 has 16 divisors (see below), whose sum is σ = 22371487509760. Its totient is φ = 19865895019200.

The previous prime is 21111222112063. The next prime is 21111222112177. The reversal of 21111222112111 is 11121122211112.

It is a cyclic number.

It is not a de Polignac number, because 21111222112111 - 2⁷ = 21111222111983 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111222112711) 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, 32664880 + ... + 33304906.

It is an arithmetic number, because the mean of its divisors is an integer number (1398217969360).

Almost surely, 2^{21111222112111} is an apocalyptic number.

21111222112111 is a deficient number, since it is larger than the sum of its proper divisors (1260265397649).

21111222112111 is a wasteful number, since it uses less digits than its factorization.

21111222112111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651694.

The product of its digits is 32, while the sum is 19.

Adding to 21111222112111 its reverse (11121122211112), we get a palindrome (32232344323223).

Subtracting from 21111222112111 its reverse (11121122211112), we obtain a palindrome (9990099900999).

The spelling of 21111222112111 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, one hundred twelve thousand, one hundred eleven".