Q: Is 661,553 a Prime Number?
A: Yes, 661,553 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 661553 can be evenly divided by 1 and 661,553, with no remainder.
Since 661,553 can be divided by just 1 and 661,553, it is a prime number.