Q: Is 391,691 a Prime Number?
A: Yes, 391,691 is a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 391691 can be evenly divided by 1 and 391,691, with no remainder.
Since 391,691 can be divided by just 1 and 391,691, it is a prime number.