Q: Is 640,121 a Prime Number?
A: Yes, 640,121 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 640121 can be evenly divided by 1 and 640,121, with no remainder.
Since 640,121 can be divided by just 1 and 640,121, it is a prime number.