Q: Is 631,640 a Prime Number?
A: No, 631,640 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 631640 can be evenly divided by 1 2 4 5 8 10 20 40 15,791 31,582 63,164 78,955 126,328 157,910 315,820 and 631,640, with no remainder.
Since 631,640 cannot be divided by just 1 and 631,640, it is not a prime number.