Q: Is 387,891 a Prime Number?
A: No, 387,891 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 387891 can be evenly divided by 1 3 7 9 21 47 63 131 141 329 393 423 917 987 1,179 2,751 2,961 6,157 8,253 18,471 43,099 55,413 129,297 and 387,891, with no remainder.
Since 387,891 cannot be divided by just 1 and 387,891, it is not a prime number.