Q: Is 643,779 a Prime Number?
A: No, 643,779 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 643779 can be evenly divided by 1 3 9 233 307 699 921 2,097 2,763 71,531 214,593 and 643,779, with no remainder.
Since 643,779 cannot be divided by just 1 and 643,779, it is not a prime number.