Q: Is 4,003,991 a Prime Number?
A: No, 4,003,991 is not a prime number.
A prime number is a natural number, greater than one, that can only be divided by 1 and itself.
The number 4003991 can be evenly divided by 1 31 53 1,643 2,437 75,547 129,161 and 4,003,991, with no remainder.
Since 4,003,991 cannot be divided by just 1 and 4,003,991, it is not a prime number.