Thus, the number 076923 would not be considered a cyclic number, because even though all cyclic permutations are multiples, they are not consecutive integer multiples: The following trivial cases are typically excluded: If leading zeros are not permitted on numerals, then 142857 is the only cyclic number in decimal, due to the necessary structure given in the next section.
For example: Multiples of these fractions exhibit cyclic permutation: From the relation to unit fractions, it can be shown that cyclic numbers are of the form of the Fermat quotient where b is the number base (10 for decimal), and p is a prime that does not divide b.
This procedure works by computing the digits of 1/p in base b, by long division.
For computers not capable of expressing very large integers, the digits may be output or collected in another way.
(Not all of these follow the second rule (all successive multiples being cyclic permutations) listed in the Special Cases section above) In each of these cases, the digits across half the period add up to the base minus one.