Answer:
Here are all possible answers I came up with:
1 × 3456 = 3,456
²
2 × 1728 = 3,456
²
3 × 1152 = 3,456
²
4 × 864 = 3,456
²
6 × 576 = 3,456
²
8 × 432 = 3,456
²
9 × 384 = 3,456
²
12 × 288 = 3,456²
16 × 216 = 3,456
²
18 × 192 = 3,456
²
24 × 144 = 3,456
²
27 × 128 = 3,456
²
32 × 108 = 3,456
²
36 × 96 = 3,456
²
48 × 72 = 3,456
²
54 × 64 = 3,456²