Which of this number is gapful<e.g. 200/20=10 because the first 2 and the last 0 is divisible by 200

Question

a gapful number is a number that is divisible by the first and last numbers

Answer 1

Gapful number is a number that is divisible by the number formed by the first and last digit of the input number

So
123
Won't be a gapful number since 123/13=9.46 something...