491191 has 4 divisors (see below), whose sum is σ = 496800. Its totient is φ = 485584.

The previous prime is 491171. The next prime is 491201. The reversal of 491191 is 191194.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191194 = 2 ⋅95597.

It is not a de Polignac number, because 491191 - 2⁵ = 491159 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 (491171) 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, 2671 + ... + 2848.

It is an arithmetic number, because the mean of its divisors is an integer number (124200).

2⁴⁹¹¹⁹¹ is an apocalyptic number.

491191 is a deficient number, since it is larger than the sum of its proper divisors (5609).

491191 is an equidigital number, since it uses as much as digits as its factorization.

491191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5608.

The product of its digits is 324, while the sum is 25.

The square root of 491191 is about 700.8501979739. The cubic root of 491191 is about 78.9011742936.

The spelling of 491191 in words is "four hundred ninety-one thousand, one hundred ninety-one".