13131...13131 (25-digits)

This number is a prime.

                                                 13131 3131313131 3131313131

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

+ The smallest palindromic prime greater than 131 formed by alternating 1 and 3. It has a square number of digits (25) and its sum of digits is also a square number (49). [Gallardo]

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