Q: Is 431,399 a Prime Number?
A: Yes, 431,399 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 431399 can be evenly divided by 1 and 431,399, with no remainder.
Since 431,399 can be divided by just 1 and 431,399, it is a prime number.