17171...17171 (31-digits)

This number is a prime.

                                          1 7171717171 7171717171 7171717171

Just showing those entries submitted by 'Silva': (Click here to show all)

+ The smallest smoothly undulating palindromic prime (SUPP) formed from digits 1 and 7. Curiously, the sum of its digits is the smallest smoothly undulating palindromic composite. [Silva]

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