Q: Is 642,557 a Prime Number?
A: Yes, 642,557 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 642557 can be evenly divided by 1 and 642,557, with no remainder.
Since 642,557 can be divided by just 1 and 642,557, it is a prime number.