5. (10 points) The sum of all four-digit numbers formed by four different non-zero digits without repetition is 106656, then the largest of these four-digit numbers is $\qquad$ , and the smallest is $\qquad$ .
【Analysis】4 distinct non-zero digits can form 24 numbers. To find the maximum and minimum values, we need to find the sum of these four digits, and then solve according to the rules of digit size.

【Solution】Let the four distinct digits be $a, b, c, d$, with $a$ as the leading digit:
$$
\begin{array}{l}
\overline{\mathrm{abcd}}+\overline{\mathrm{abdc}}+\overline{\mathrm{acbd}}+\overline{\mathrm{acdb}}+\overline{\mathrm{adbc}}+\overline{\mathrm{adcb}}=6000 a+200(b+c+d)+20(b+c+d)+2(b+c+d) \\
=6000 a+222(b+c+d)
\end{array}
$$

Similarly, for $b$ as the leading digit:
$$
\overline{\mathrm{bacd}}+\overline{\mathrm{badc}}+\overline{\mathrm{bcad}}+\overline{\mathrm{bcda}}+\overline{\mathrm{bdac}}+\overline{\mathrm{bdca}}=6000 b+200(a+c+d)+20(a+c+d)+2(a+c+d) \\
=6000 b+222(a+c+d)
$$
For $c$ as the leading digit:
$$
\overline{\mathrm{cabd}}+\overline{\mathrm{cadb}}+\overline{\mathrm{cbad}}+\overline{\mathrm{cbda}}+\overline{\mathrm{cdab}}+\overline{\mathrm{cdba}}=6000 c+200(b+c+d)+20(b+c+d)+2(b+c+d) \\
=6000 c+222(b+c+d)
$$
$$
\begin{array}{l}
d \text { as the leading digit: } \overline{\mathrm{dabc}}+\overline{\mathrm{dcab}}+\overline{\mathrm{dbac}}+\overline{\mathrm{dbca}}+\overline{\mathrm{dcab}}+\overline{\mathrm{dcba}}=6000 d+200(a+b+c)+20(a+b+c)+2(a+b+c) \\
=6000 d+222(a+b+c) \\
6000 a+222(b+c+d)+6000 b+222(a+c+d)+6000 c+222(b+c+d)+6000 d+222(a+b+c) \\
=6000(a+b+c+d)+222(3 a+3 b+3 c+3 d) \\
=6666(a+b+c+d) \\
=106656 \\
\therefore a+b+c+d=16
\end{array}
$$

To maximize the four-digit number, the thousands place should be as large as possible, and the units place should be as small as possible. At the same time, the digits must be distinct, so the thousands place is 9, the units place is 1, and the tens place is 2.

The hundreds place is $16-9-1-2=4$. Therefore, the maximum number is 9421. The minimum number is when the digits are in ascending order, i.e., 1249. Hence, the answer is: 9421, 1249.