2111212111 has 4 divisors (see below), whose sum is σ = 2115512424. Its totient is φ = 2106911800.

The previous prime is 2111212097. The next prime is 2111212157. The reversal of 2111212111 is 1112121112.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 2111212111 - 2⁷ = 2111211983 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2111212091 and 2111212100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111212211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2149420 + ... + 2150401.

It is an arithmetic number, because the mean of its divisors is an integer number (528878106).

Almost surely, 2^2111212111 is an apocalyptic number.

2111212111 is a deficient number, since it is larger than the sum of its proper divisors (4300313).

2111212111 is an equidigital number, since it uses as much as digits as its factorization.

2111212111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4300312.

The product of its digits is 8, while the sum is 13.

The square root of 2111212111 is about 45947.9282557984. The cubic root of 2111212111 is about 1282.8541678987.

Adding to 2111212111 its reverse (1112121112), we get a palindrome (3223333223).

Subtracting from 2111212111 its reverse (1112121112), we obtain a palindrome (999090999).

It can be divided in two parts, 2 and 111212111, that multiplied together give a palindrome (222424222).

The spelling of 2111212111 in words is "two billion, one hundred eleven million, two hundred twelve thousand, one hundred eleven".