A palindrome number is a number that is the same forwards as backwards. Some examples are 3443, 12321, and 59095.
Here's my question: What is the largest 12 digit palindrome that is evenly divisible by 7?
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$\begingroup$ Vote to close as a math Q $\endgroup$– ghosts_in_the_codeCommented Jan 2, 2016 at 10:52
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2 Answers
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It would appear that the largest 12 digit number, 999,999,999,999 is divisible by 7 and is also a palindrome. So that must be the largest 12 digit palindrome divisible by 7
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999,999,999,999 as Stephen mentioned is divisible by 7. Just for fun, here are the next nine largest ones:
999992299999
999989989999
999982289999
999979979999
999972279999
999969969999
999962269999
999959959999
999952259999
If we're not allowing for repeated digits in each half, the largest ten would be:
987654456789**
987634436789
987624426789
987614416789
987604406789
987563365789
987543345789
987523325789
987513315789
987503305789
** = I just find it interesting that in both cases, the largest acceptable answer is unaffected by the "divisible by 7" clause.
