Q: Is 664,521 a Prime Number?
A: No, 664,521 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 664521 can be evenly divided by 1 3 11 13 33 39 143 429 1,549 4,647 17,039 20,137 51,117 60,411 221,507 and 664,521, with no remainder.
Since 664,521 cannot be divided by just 1 and 664,521, it is not a prime number.