There is no number with the given list as its only proper factors.
As 2 and 5 are both proper factors of the number, 10 must also be a proper factor of the number, but you have not listed it.
Dropping the proper factor 5 and adding the proper factor 21 allows the number to be 2 x 294 = 588.
All factors of a number have a pair which when multiplied together give the number.
The first proper factor of all numbers is 1 and would pair with the number itself. The second proper factor pairs with the last proper factor, the third with the second to last and so on. If this leaves one factor unpaired, the number is a perfect square of this factor.
For your list (corrected):
The number = 1 x number
= 2 x 294
= 3 x 196
= 4 x 147
= 6 x 98
= 7 x 84
= 12 x 49
= 14 x 42
= 21 x 28
For your list, the lowest number which has all those factors is 2940 which also has the extra proper factors: 10, 15, 20, 21, 30, 35, 60, 70, 105, 140, 210, 245, 420, 490, 588, 735, 980 & 1470
Another answer:
There's a problem here. There are two definitions of proper factors. One leaves out the number itself, and the other leaves out one and the number itself. Since you've included one, we'll go with the first definition. Since the last number has been removed, that would mean that the number you're looking for would be the product of the second number (2) and the second to last number (294) or the third number (3) and the third to last number (196) and so on. Both of these are 588. But the list you've notated is not the proper factors of 588. Take out the 5 and add a 21 and you will have listed the proper factors of 588.
1: 1
2: 1, 2
3: 1, 3
4: 1, 2, 4
6: 1, 2, 3, 6
12: 1, 2, 3, 4, 6, 12
18: 1, 2, 3, 6, 9, 18
24: 1, 2, 3, 4, 6, 8, 12, 24
36: 1, 2, 3, 4, 6, 9, 12, 18, 36
72: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72
(588,1)(294,2)(196,3)(147,4)(98,6)(84,7)(49,12)(42,14)(28,21)
The factor pairs of 294 are (294, 1) (147, 2) (98, 3) (49, 6) (42, 7) (21, 14) None of them add up to 7. If that was -294, you could use 21 and -14
2 x 294 3 x 196 4 x 147 6 x 98 7 x 84 12 x 49 14 x 42 21 x 28
2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 49, 84, 98, 147, 196, 294
49, 98, 147, 196, 245, 294, 343, 392, 441, 490.
There are 9 factor pairs of 588.588 = 1 x 588588 = 2 x 294588 = 3 x 196588 = 4 x 147588 = 6 x 98588 = 7 x 84588 = 12 x 49588 = 14 x 42588 = 21 x 28
The Greatest Common Factor (GCF) of 294 and 196 is 98.
(588,1)(294,2)(196,3)(147,4)(98,6)(84,7)(49,12)(42,14)(28,21)
Any multiple of 588
49, 98, 147, 196, 245, 294, 343 . . .
The factor pairs of 294 are (294, 1) (147, 2) (98, 3) (49, 6) (42, 7) (21, 14) None of them add up to 7. If that was -294, you could use 21 and -14
The factors of 196 are: 1, 2, 4, 7, 14, 28, 49, 98, 196 The factors of 294 are: 1, 2, 3, 6, 7, 14, 21, 42, 49, 98, 147, 294
No, 294 is not a proper factor of 147. Proper factors are smaller than the number of which they are a factor. The proper factors of 147 are 3, 7, 21, 49, and perhaps 1, depending on the definition you are using.
Any positive integer, k, is a factor because it will divide larger integers of the form 2k, 3k etc. 147 divides 294, for example and so is a factor of 294.
(1764, 1) (882, 2) (588, 3) (441, 4) (294, 6) (252, 7) (196, 9) (147, 12) (126, 14) (98, 18) (84, 21) (63, 28) (49, 36) (42, 42)
The GCF is 98.
588
2 x 294 3 x 196 4 x 147 6 x 98 7 x 84 12 x 49 14 x 42 21 x 28