5103 is not divisible by two because it does not end in a even number but it is divisible by 3 because all of the numbers put together equals 9 and nine is a multiple of three. This means it is not divisible by six because it is not divisible by two.
3463 is not divisible by two because it does not end with an even number. it is not divisible by three ever because all of it together equals sixteen so it is not divisible by three ever which means it is not divisible by six.