- Jul 8, 2011--- In primenumbers@yahoogroups.com,

"Mark" <mark.underwood@...> wrote:

> Every composite number has its weakness.

This is true, in a unhelpful way. Suppose that N is divisible

> There will be some base in which to express such a number,

> which eyeballing will reveal to be composite.

by b, where N > b > 1. Then N ends in 0, when written in base b.

As remarked, this not particularly helpful :-)

David - << Previous post in topic