2121111191 has 2 divisors, whose sum is σ = 2121111192. Its totient is φ = 2121111190.

The previous prime is 2121111149. The next prime is 2121111193. The reversal of 2121111191 is 1911111212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2121111191 is a prime.

It is a super-2 number, since 2×2121111191² = 8998225369170876962, which contains 22 as substring.

Together with 2121111193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121111193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060555595 + 1060555596.

It is an arithmetic number, because the mean of its divisors is an integer number (1060555596).

Almost surely, 2^2121111191 is an apocalyptic number.

2121111191 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121111191 is an equidigital number, since it uses as much as digits as its factorization.

2121111191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36, while the sum is 20.

The square root of 2121111191 is about 46055.5229152813. The cubic root of 2121111191 is about 1284.8560636571.

The spelling of 2121111191 in words is "two billion, one hundred twenty-one million, one hundred eleven thousand, one hundred ninety-one".