191091133 has 4 divisors (see below), whose sum is σ = 191123680. Its totient is φ = 191058588.

The previous prime is 191091073. The next prime is 191091139. The reversal of 191091133 is 331190191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191091133 is a prime.

It is a super-2 number, since 2×191091133² = 73031642222447378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191091139) 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 in 3 ways as a sum of consecutive naturals, for example, 4743 + ... + 20116.

It is an arithmetic number, because the mean of its divisors is an integer number (47780920).

Almost surely, 2^191091133 is an apocalyptic number.

It is an amenable number.

191091133 is a deficient number, since it is larger than the sum of its proper divisors (32547).

191091133 is an equidigital number, since it uses as much as digits as its factorization.

191091133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32546.

The product of its (nonzero) digits is 729, while the sum is 28.

The square root of 191091133 is about 13823.5716441157. The cubic root of 191091133 is about 575.9881011640.

The spelling of 191091133 in words is "one hundred ninety-one million, ninety-one thousand, one hundred thirty-three".