Apart from [1,201], [3,67] is the only other factor pair.
Since both 3 and 67 are prime numbers, you know you won't be able to find any more factor pairs.
1x40, 2x20, 4x10, 5x8 are all the factor pairs of 40.
The factor pairs for 38 are (1, 19) and (2, 38).
The factor pairs of 26 are: 1 × 26 2 × 13
The factor tree of 201 is: 3 x 67 The factors of 201 are: 1, 3, 67, 201.
The factor pairs of 20 are pairs of numbers that can be multiplied together to give 20. The factor pairs of 20 are (1, 20), (2, 10), and (4, 5). These pairs represent all the possible combinations of numbers that can be multiplied to equal 20.
201 3,67
They are:165,155,333,515,11
1,81,3,27,9
They are:200,1100,250,440,525,820,10
51,117,3
612,1306,2204,3153,4102,668,951,1236,1734,18
164,182,241,4