Q: Is 278,639 a Prime Number?
A: Yes, 278,639 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 278639 can be evenly divided by 1 and 278,639, with no remainder.
Since 278,639 can be divided by just 1 and 278,639, it is a prime number.