1) Find all the 0 to 9 pandigital numbers (without leading zero) that
have the largest power of 3 as a factor.
2) One of these numbers has a very interesting property. What is it?
*an x to y pandigital number is an integer that contains all the digits from x to y and only those digits once each, for example 1234 is 1 to 4 pandigital but not 1 to 9 pandigital*
There are nine qualifying numbers which are divisible by 3 ** 14 (including the one also divisible by 3 ** 15). Evidently Daniel saw something in one of these nine that piqued his attention. My own vote would be for the Hardy-Ramanujan Number, which is the lowest integer which is the sum of two positive-integer cubes in two different ways (I'd put Sri R's name first!). It yields 8269753401. Jer's property is notable (and, of course, also relies on division by 3**15) -- though most reciprocals wind up with repeating decimals -- and 1980 was the year that brought us Reagan, our last congenial prexy. The only distinction I see for 1515 is that it shares no digits with 3**14 (4782969).