Solution: The number must be divisible by the least common multiple (LCM) of 7, 11, and 13. Since these are all primes, LCM = 7 × 11 × 13 = 1001. The smallest four-digit number is the first multiple of 1001 ≥ 1000, which is $1001 imes 1 = 1001$. Thus, the answer is $oxed1001$. - Portal da Acústica