You can improve your solution significantly using maths. You need to find a number that multiplied by 1080 will given a remainder 6 modulo 7 (because after adding 1 it should be divisible by 7). Now 1080 gives remainder 2 modulo 7. Thus you need to find number that multiplied by 2 gives 6 modulo 7. Lets check all 7 possible remainders:
0 * 2 = 0 (modulo 7)
1 * 2 = 2 (modulo 7)
2 * 2 = 4 (modulo 7)
3 * 2 = 6 (modulo 7)
4 * 2 = 1 (modulo 7)
5 * 2 = 3 (modulo 7)
6 * 2 = 5 (modulo 7)
So the only solutions to your problem are the numbers giving remainder 3 (modulo 7)
and all such numbers are solutions of the equation.