Q: Is 645,428 a Prime Number?
A: No, 645,428 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 645428 can be evenly divided by 1 2 4 7 14 28 37 49 74 89 98 148 178 196 259 356 518 623 1,036 1,246 1,813 2,492 3,293 3,626 4,361 6,586 7,252 8,722 13,172 17,444 23,051 46,102 92,204 161,357 322,714 and 645,428, with no remainder.
Since 645,428 cannot be divided by just 1 and 645,428, it is not a prime number.