173□ is a four-digit number. The math teacher said: "I filled in 3 numbers successively in this □, and the 3 four-digit numbers I got are divisible by 9, 11, and 6 in sequence." Question: The sum of the 3 numbers filled in by the math teacher successively how many?
173□是个四位数字．数学老师说："我在这个□中先后填入3个数字，所得到的3个四位数，依次可被9、11、6整除．"问：数学老师先后填入的3个数字的和是多少？
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">7 + 8 + 4</gadget>
<output>19</output>

<result>19</result>