171191 has 4 divisors (see below), whose sum is σ = 172272. Its totient is φ = 170112.

The previous prime is 171179. The next prime is 171203. The reversal of 171191 is 191171.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 191171 = 53 ⋅3607.

It is an interprime number because it is at equal distance from previous prime (171179) and next prime (171203).

It is a cyclic number.

It is not a de Polignac number, because 171191 - 2¹⁰ = 170167 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 (171131) 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, 251 + ... + 636.

It is an arithmetic number, because the mean of its divisors is an integer number (43068).

2¹⁷¹¹⁹¹ is an apocalyptic number.

171191 is a deficient number, since it is larger than the sum of its proper divisors (1081).

171191 is an equidigital number, since it uses as much as digits as its factorization.

171191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080.

The product of its digits is 63, while the sum is 20.

The square root of 171191 is about 413.7523413831. The cubic root of 171191 is about 55.5256489406.

Subtracting from 171191 its sum of digits (20), we obtain a palindrome (171171).

The spelling of 171191 in words is "one hundred seventy-one thousand, one hundred ninety-one".