I think that's a different problem, although it is not entirely irrelevant since having a small prime factor like 3 implies that that the method will fail in at least 1/3 of the cases.
The other problem is that the value φ(n) will be wrong, even then there are some rare cases where the method might still work (see eximius comment about carmicheal numbers) but those are exceedingly rare.
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I think that's a different problem, although it is not entirely irrelevant since having a small prime factor like 3 implies that that the method will fail in at least 1/3 of the cases.
The other problem is that the value φ(n) will be wrong, even then there are some rare cases where the method might still work (see eximius comment about carmicheal numbers) but those are exceedingly rare.