1311111191 has 16 divisors (see below), whose sum is σ = 1443204000. Its totient is φ = 1183628160.

The previous prime is 1311111181. The next prime is 1311111203. The reversal of 1311111191 is 1911111131.

It is not a de Polignac number, because 1311111191 - 2¹⁸ = 1310849047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1311111101) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 225185 + ... + 230933.

It is an arithmetic number, because the mean of its divisors is an integer number (90200250).

Almost surely, 2^1311111191 is an apocalyptic number.

1311111191 is a deficient number, since it is larger than the sum of its proper divisors (132092809).

1311111191 is a wasteful number, since it uses less digits than its factorization.

1311111191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6146.

The product of its digits is 27, while the sum is 20.

The square root of 1311111191 is about 36209.2694071560. The cubic root of 1311111191 is about 1094.4934699133.

The spelling of 1311111191 in words is "one billion, three hundred eleven million, one hundred eleven thousand, one hundred ninety-one".