1131122191 has 4 divisors (see below), whose sum is σ = 1131567112. Its totient is φ = 1130677272.

The previous prime is 1131122143. The next prime is 1131122233. The reversal of 1131122191 is 1912211311.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1912211311 = 5153 ⋅371087.

It is a cyclic number.

It is not a de Polignac number, because 1131122191 - 2⁹ = 1131121679 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 (1131122491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 218625 + ... + 223738.

It is an arithmetic number, because the mean of its divisors is an integer number (282891778).

Almost surely, 2^1131122191 is an apocalyptic number.

1131122191 is a deficient number, since it is larger than the sum of its proper divisors (444921).

1131122191 is an equidigital number, since it uses as much as digits as its factorization.

1131122191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444920.

The product of its digits is 108, while the sum is 22.

The square root of 1131122191 is about 33632.1600703850. The cubic root of 1131122191 is about 1041.9251173894.

The spelling of 1131122191 in words is "one billion, one hundred thirty-one million, one hundred twenty-two thousand, one hundred ninety-one".