11211211112111 has 4 divisors (see below), whose sum is σ = 11211218705400. Its totient is φ = 11211203518824.

The previous prime is 11211211112099. The next prime is 11211211112203. The reversal of 11211211112111 is 11121111211211.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11211211112111 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 11211211112111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211211112911) 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, 786341 + ... + 4800078.

It is an arithmetic number, because the mean of its divisors is an integer number (2802804676350).

Almost surely, 2^{11211211112111} is an apocalyptic number.

11211211112111 is a deficient number, since it is larger than the sum of its proper divisors (7593289).

11211211112111 is an equidigital number, since it uses as much as digits as its factorization.

11211211112111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7593288.

The product of its digits is 8, while the sum is 17.

Adding to 11211211112111 its reverse (11121111211211), we get a palindrome (22332322323322).

The spelling of 11211211112111 in words is "eleven trillion, two hundred eleven billion, two hundred eleven million, one hundred twelve thousand, one hundred eleven".