2111122121 has 4 divisors (see below), whose sum is σ = 2111221200. Its totient is φ = 2111023044.

The previous prime is 2111122081. The next prime is 2111122147. The reversal of 2111122121 is 1212211112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, 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-2111122121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2111122096 and 2111122105.

It is not an unprimeable number, because it can be changed into a prime (2111122151) 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, 3011 + ... + 65048.

It is an arithmetic number, because the mean of its divisors is an integer number (527805300).

Almost surely, 2^2111122121 is an apocalyptic number.

It is an amenable number.

2111122121 is a deficient number, since it is larger than the sum of its proper divisors (99079).

2111122121 is an equidigital number, since it uses as much as digits as its factorization.

2111122121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99078.

The product of its digits is 16, while the sum is 14.

The square root of 2111122121 is about 45946.9489846714. The cubic root of 2111122121 is about 1282.8359405043.

Adding to 2111122121 its reverse (1212211112), we get a palindrome (3323333233).

The spelling of 2111122121 in words is "two billion, one hundred eleven million, one hundred twenty-two thousand, one hundred twenty-one".