The number 142857 has some very interesting properties. It is very easy to remember how to multiply it with 2, 3, 4, 5, 6, 7 and even bigger numbers.

142857 * 2 = 285714
142857 * 3 = 428571
142857 * 4 = 571428
142857 * 5 = 714285
142857 * 6 = 857142
142857 * 7 = 999999

The results after multiplication with a number from 2 to 6 gives circular permutations of the original number.