About the Number 191 (one hundred ninety-one)

While updating the Eisenstein Primes collection to include the number 593, MathBabbler noticed that there wasn't a nBAB for the number 191. Note: 191 is also an Eisenstein prime.

RoadHacker has done lots of roadtripping on US Hwy-191.

   MathBabbler 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

191 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.

The following items were copied from NumberGossip.com.

   191 is the smallest palindromic prime whose sum of digits 
       is a multidigit palindromic prime

   By adding up the values of the common US coins, one obtains 
   191 cents. (silver dollar + half dollar + quarter + 
               dime + nickel + penny)

19116 equals 401 and 401 is an Eisenstein prime.


Creator: Gerald Thurman [gthurman@gmail.com]
Created: 11 July 2009

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