Well bud, I'm going to have to fucking sage you in the math forum for not knowing how decimal fractions work. The chain would obviously be longer than the screen on your calculator. As dividing by 7 gives a six digit sequence of ...142857..., 13 gives one of 2 sequences of 6 digits, a number divided by 1667 would in theory have a repeated chain of 1666 digits, or the possibility that smaller sub-chains repeat themselves for that length when collated together.