Let the 6 digit number be _ _ _ 42 _ It is divisible by 2,3,5,7,11,13 Since the number is divisible by both 2 and 5 the last digit of the number must be 0. The number is also divisible by 7,11, and 13. Hence the number must also be divisible by 7×11×13=7×11×13=1001. A number which is a multiple of 1001 is of the form abcabc. This is because abc×(1001)=abc×(1000+1)=abc000+abc=abcabc. Hence the number is 420420. The first digit is 4.