Q: Is 641,623 a Prime Number?
A: Yes, 641,623 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 641623 can be evenly divided by 1 and 641,623, with no remainder.
Since 641,623 can be divided by just 1 and 641,623, it is a prime number.