21112221110111 has 4 divisors (see below), whose sum is σ = 21132308857224. Its totient is φ = 21092133363000.

The previous prime is 21112221110093. The next prime is 21112221110129. The reversal of 21112221110111 is 11101112221112.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21112221110093) and next prime (21112221110129).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112221110111 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21112221110111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112221110171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10043871980 + ... + 10043874081.

It is an arithmetic number, because the mean of its divisors is an integer number (5283077214306).

Almost surely, 2^{21112221110111} is an apocalyptic number.

21112221110111 is a deficient number, since it is larger than the sum of its proper divisors (20087747113).

21112221110111 is a wasteful number, since it uses less digits than its factorization.

21112221110111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20087747112.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 21112221110111 its reverse (11101112221112), we get a palindrome (32213333331223).

The spelling of 21112221110111 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty-one million, one hundred ten thousand, one hundred eleven".