(1) For a cube, its edge length is 4cm. Dig out a cube with an edge length of 1cm at the middle of its top, bottom, front, back, left and right. What's the surface area of the remaining figure? (2) Interesting three digits: Write any three digits twice to form a six digit number, such as 346 → 345345, then it can be divided by 7. Can you explain the reason? Is there any other divisor for this six digit number?

(1) For a cube, its edge length is 4cm. Dig out a cube with an edge length of 1cm at the middle of its top, bottom, front, back, left and right. What's the surface area of the remaining figure? (2) Interesting three digits: Write any three digits twice to form a six digit number, such as 346 → 345345, then it can be divided by 7. Can you explain the reason? Is there any other divisor for this six digit number?

Previous surface area: 4 * 4 * 6 = 96 square centimeters
Add four 1 * 1:1 * 1 * 4 * 6 to each surface = 24 square centimeters
Total: 96 + 24 = 120 square centimeters
To write two times to make six digits is to multiply the three digits by 1001, and 1001 = 7 * 11 * 13, so it can be divided by 7. The other divisors are: 11, 13 and the divisor of the three digits