291191 has 2 divisors, whose sum is σ = 291192. Its totient is φ = 291190.

The previous prime is 291173. The next prime is 291199. The reversal of 291191 is 191192.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-291191 is a prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (291199) 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 as a sum of consecutive naturals, namely, 145595 + 145596.

It is an arithmetic number, because the mean of its divisors is an integer number (145596).

2²⁹¹¹⁹¹ is an apocalyptic number.

291191 is a deficient number, since it is larger than the sum of its proper divisors (1).

291191 is an equidigital number, since it uses as much as digits as its factorization.

291191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 162, while the sum is 23.

The square root of 291191 is about 539.6211634100. The cubic root of 291191 is about 66.2815489940.

Subtracting from 291191 its reverse (191192), we obtain a palindrome (99999).

The spelling of 291191 in words is "two hundred ninety-one thousand, one hundred ninety-one".