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Prime+reversal= prime (Posted on 2014-03-04)

Find the smallest prime which can be represented as sum of a prime and its reversal.

See The Solution Submitted by Ady TZIDON

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Master of the obvious

| Comment 3 of 4 |

The prime that is being reversed and then added to itself to form a new prime must:

a) have an odd number of digits, because any number with an even number of digits, when added to its reversal, is divisible by 11

b) start with an even number, in order that the resulting sum end in an odd number

Posted by Steve Herman on 2014-03-04 16:40:31

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