While updating the Eisenstein Primes collection to include the number 593, MathBabbler noticed that there wasn't a nBAB for the number

`. Note:`

191`is also an Eisenstein prime.`

191RoadHacker has done lots of roadtripping on US Hwy-

`.`

191MathBabbler Number Analyst (MBNA) output: ========================================= 191 is a natural, whole, integer 191 is odd 191 proper divisors are: 1, 191 is deficient (sum of divisors is 1) 191 is unhappy 191 is not a Harshad number 191 is prime ...Sexy prime with 197 ...Sophie Germain prime with 383 ...Twin prime with 193 ...OEIS:002145 (4n+3; n=47) ...Super ...Right-truncatable ...Eisenstein ...prime triplet {191, 193, 197} ...prime quadruplet {191, 193, 197, 199} 191 is undulating 191 is palindromic 191 is a Thabit number 191 in octal is 0277 191 in hexadecimal is 0xbf 191 in binary is 10111111 (is odious) 191 nearest square numbers: -22...5 (169...196 [14]) sqrt(191) = 13.8203 ln(191) = 5.25227 log(191) = 2.28103 191 reciprocal is .00523560209424083769633507853403 191! is 1.84894e+354 191 is 60.7972 Pi years 191 is 9 score and 11 years 191 written as a Roman numeral is CXCI

`is a Sexy prime with 197 and 197 is an Eisenstein prime.`

191

`is a Sophie Germain prime with 383 and 383 is an Eisenstein prime.`

191The following items were copied from NumberGossip.com.

191is the smallest palindromic prime whose sum of digits is a multidigit palindromic prime By adding up the values of the common US coins, one obtains191cents. (silver dollar + half dollar + quarter + dime + nickel + penny)

191_{16}equals 401 and 401 is an Eisenstein prime.

**Creator:** Gerald Thurman
[gthurman@gmail.com]

**Created:** 11 July 2009

This work is licensed under a Creative Commons Attribution 3.0 United States License.