2111212121111 has 4 divisors (see below), whose sum is σ = 2111425363224. Its totient is φ = 2110998879000.

The previous prime is 2111212121087. The next prime is 2111212121147. The reversal of 2111212121111 is 1111212121112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2111212121111 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 2111212121111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111272121111) 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, 106606205 + ... + 106626006.

It is an arithmetic number, because the mean of its divisors is an integer number (527856340806).

Almost surely, 2^{2111212121111} is an apocalyptic number.

2111212121111 is a deficient number, since it is larger than the sum of its proper divisors (213242113).

2111212121111 is an equidigital number, since it uses as much as digits as its factorization.

2111212121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213242112.

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

Adding to 2111212121111 its reverse (1111212121112), we get a palindrome (3222424242223).

Subtracting from 2111212121111 its reverse (1111212121112), we obtain a palindrome (999999999999).

The spelling of 2111212121111 in words is "two trillion, one hundred eleven billion, two hundred twelve million, one hundred twenty-one thousand, one hundred eleven".