1311121111 has 2 divisors, whose sum is σ = 1311121112. Its totient is φ = 1311121110.

The previous prime is 1311121067. The next prime is 1311121153. The reversal of 1311121111 is 1111211131.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1311121111 - 2⁷ = 1311120983 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1311121091 and 1311121100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1311131111) 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, 655560555 + 655560556.

It is an arithmetic number, because the mean of its divisors is an integer number (655560556).

Almost surely, 2^1311121111 is an apocalyptic number.

1311121111 is a deficient number, since it is larger than the sum of its proper divisors (1).

1311121111 is an equidigital number, since it uses as much as digits as its factorization.

1311121111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6, while the sum is 13.

The square root of 1311121111 is about 36209.4063883958. The cubic root of 1311121111 is about 1094.4962302558.

Adding to 1311121111 its reverse (1111211131), we get a palindrome (2422332242).

The spelling of 1311121111 in words is "one billion, three hundred eleven million, one hundred twenty-one thousand, one hundred eleven".