FANDOM


191 is a prime number from 101-200. 191 has 2 factors, 1 and 191. It is the 43rd prime number, and the eighteenth prime number from 101-200.

Proofs

  • Yes — 191 can be divided by 1.
  • No — 191 cannot be divided by 2-190.
  • Yes — 191 can be divided by 191.


As an Exponent of Mersenne Number

2191 - 1 is divisible by number such as 383 and 7,068,569,257, and is therefore not a prime number.

Relationship with other odd numbers

The numbers before

  • The previous prime number is 181.
    • Notably, 187 is not a prime number. It can be factored as 11 x 17.
  • The previous prime number before 181 is 179.

The numbers after

  • The next prime number is 193.
    • There are no odd numbers between 191 and 193. As a result, they are twin primes.
  • 197 is the next prime number after 193.
    • 191 and 197 are six numbers apart; therefore, they are sexy primes.