The only way this can be done with integers is 1 x 7. Obviously there are a whole range of non-integers that can do this e.g. 2 x 3.5 4 x 1.75 14 x 0.5 28 x 0.25 etc but the only whole numbers are 1 x 7.
The two numbers you multiply together to equal 391 are 17 by 23.
-30
-936
17
-62 and 70
The two numbers you can multiply together to equal 782 are 23 by 34.
The two numbers you multiply together to equal 391 are 17 by 23.
-30
20
The 2 numbers that multiply together to equal 678 are 6 and 113.
-17
-936
-117
17
-21, 27
22
1025 and 2.