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A comment on Is this prime?. Parent comment

Re:Is this prime? by cousin_it on Tuesday March 08, 2016 @01:48PM (#11247477)
Counterexample: 209. The even more general test is that the alternating sum of digits is divisible by 11.
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Re:Is this prime? by sdenton4 on Tuesday March 08, 2016 @11:54PM (#11251016)
(I'll pretend to defend myself and say I meant zero mod eleven. :) )
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