Q: Is 391,999 a Prime Number?
A: Yes, 391,999 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 391999 can be evenly divided by 1 and 391,999, with no remainder.
Since 391,999 can be divided by just 1 and 391,999, it is a prime number.