Q: Is 278,405 a Prime Number?
A: No, 278,405 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 278405 can be evenly divided by 1 5 55,681 and 278,405, with no remainder.
Since 278,405 cannot be divided by just 1 and 278,405, it is not a prime number.