1311111611 has 4 divisors (see below), whose sum is σ = 1311185400. Its totient is φ = 1311037824.

The previous prime is 1311111601. The next prime is 1311111661. The reversal of 1311111611 is 1161111131.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1311111611 - 2²² = 1306917307 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1311111611.

It is not an unprimeable number, because it can be changed into a prime (1311111601) 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, 7835 + ... + 51803.

It is an arithmetic number, because the mean of its divisors is an integer number (327796350).

Almost surely, 2^1311111611 is an apocalyptic number.

1311111611 is a deficient number, since it is larger than the sum of its proper divisors (73789).

1311111611 is an equidigital number, since it uses as much as digits as its factorization.

1311111611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73788.

The product of its digits is 18, while the sum is 17.

The square root of 1311111611 is about 36209.2752067754. The cubic root of 1311111611 is about 1094.4935867830.

Adding to 1311111611 its reverse (1161111131), we get a palindrome (2472222742).

The spelling of 1311111611 in words is "one billion, three hundred eleven million, one hundred eleven thousand, six hundred eleven".