1191311 has 4 divisors (see below), whose sum is σ = 1299624. Its totient is φ = 1083000.

The previous prime is 1191301. The next prime is 1191313. The reversal of 1191311 is 1131911.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1191311 - 2⁶ = 1191247 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 1191311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54140 + ... + 54161.

It is an arithmetic number, because the mean of its divisors is an integer number (324906).

2^1191311 is an apocalyptic number.

1191311 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1191311 is a deficient number, since it is larger than the sum of its proper divisors (108313).

1191311 is a wasteful number, since it uses less digits than its factorization.

1191311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108312.

The product of its digits is 27, while the sum is 17.

The square root of 1191311 is about 1091.4719419206. The cubic root of 1191311 is about 106.0087509092.

The spelling of 1191311 in words is "one million, one hundred ninety-one thousand, three hundred eleven".