Special Pens

Ravi just started a factory of fountain pens. Every pen has a production number on it. He considers a pen as lucky if the difference between the sum of digits at even place and sum of digits at odd place of the production number of pen is a positive multiple of 3 or 5 or 7. (indexing starts from the unit's place, with unit's place location being 1, ten's place as 2, hundred's place as 3 and so on)