2. (5 points) 21 baskets, each basket contains 48 eggs, now pack these eggs into some boxes, each box holds 28 eggs, can be packed.
36
【Analysis】According to the meaning of multiplication, we can calculate the total number of eggs by multiplying 21 by 48, and then according to the meaning of division, we can calculate the number of boxes needed by dividing the total number of eggs by 28.
【Solution】Solution: $21 \times 48 \div 28$
$$
\begin{array}{l}
=1008 \div 28 \\
=36 \text { (boxes) }
\end{array}
$$

Answer: 36 boxes can be filled.
Therefore, the answer is: 36.