The number has to be form
10000x+1000y+100z+10y+z
= 10001x+ 1010y + 100z
10001x + 1010y+100z mod 7 = 5x + 2y + 2z mod 7
x cannot be < 5. so let x = 5 and let us look for solution y minimum 6
so 25+2y+2z mod 7 = 0 or 2y+2z = 3 mod 7 or y + z = 5 mod 7
y+z = 5 no solution
so y + z = 12 if y = 6 z = 6 not possible
so y = 7 and z = 5 possible
number = 57575
it is 7 * 8225
if we did not find a solution with x = 5 then we should have tried at x = 6
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