1111211111 has 2 divisors, whose sum is σ = 1111211112. Its totient is φ = 1111211110.

The previous prime is 1111211063. The next prime is 1111211113. The reversal of 1111211111 is 1111121111.

It is a happy number.

It is a m-pointer prime, because the next prime (1111211113) can be obtained adding 1111211111 to its product of digits (2).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1111211111 - 2³⁰ = 37469287 is a prime.

Together with 1111211113, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1111211092 and 1111211101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1111211113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 555605555 + 555605556.

It is an arithmetic number, because the mean of its divisors is an integer number (555605556).

Almost surely, 2^1111211111 is an apocalyptic number.

1111211111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1111211111 is an equidigital number, since it uses as much as digits as its factorization.

1111211111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2, while the sum is 11.

The square root of 1111211111 is about 33334.8332979183. The cubic root of 1111211111 is about 1035.7752400097.

Adding to 1111211111 its reverse (1111121111), we get a palindrome (2222332222).

Subtracting from 1111211111 its reverse (1111121111), we obtain a square (90000 = 300²).

The spelling of 1111211111 in words is "one billion, one hundred eleven million, two hundred eleven thousand, one hundred eleven".