Yes having an 840 insurance score is a pretty good insurance score to have.
The higher your insurance score number the better as your insurance score affects your insurance rates and shows how good of a risk you are to the insurance companies.
The higher your insurance score number the lower your insurance premiums usually are and the lower your insurance score number the higher your insurance rates usually are.
So you want the insurance score to be as high as possible for the cheapest insurance rates on auto insurance, homeowners insurance, renters insurance etc.
Auto Insurance score numbers range from as low as 200 to as high as 997 and any insurance score of 770 or higher is considered to be a good insurance score.
So yes your 840 insurance score is a good insurance score and should get you cheap auto insurance and other insurance rates.