Q: Is 128,521 a Prime Number?
A: Yes, 128,521 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 128521 can be evenly divided by 1 and 128,521, with no remainder.
Since 128,521 can be divided by just 1 and 128,521, it is a prime number.