Apple faces a threat to around 20% of its earnings if two legal threats turn out badly for the company, according to Evercore analysts.

Apple faces two major risks -- the first is the end of the arrangement where it receives billions of dollars annually from Google-parent Alphabet for placement of its search engine on iPhones. The second is litigation with videogame developer Epic Games that threatens its ability to charge a fee on transactions in Apple's App Store.

The payment from Google -- estimated at $20 billion to $24 billion -- is the bigger deal, representing around 6% of Apple's annual revenue but 16% of its earnings per share, according to Evercore's Amit Daryanani.

Now the Department of Justice has proposed that Google should be prohibited from providing Apple with "anything of value" for search placement as part of an antitrust lawsuit against the search-engine company.

"We estimate 50% of the total payment from Google is for U.S. revenue sharing," wrote Daryanani. "The DOJ would not be able to challenge the non-US payments. There is some risk however that Google chooses to simply drop the entire agreement if it is ruled to be illegal in the U.S."

Meanwhile, Apple also risks losing money it earns from charging fees to U.S. app developers, after a California judge recently ruled the company violated a 2021 injunction requiring it to allow app makers to steer users to in-app payment methods not controlled by the company.

The total revenue at risk there is an estimated $7 billion, representing 2% of revenue but around 6% of the company's earnings per share, according to Daryanani.

Apple has filed an emergency motion to temporarily fend off the ordered changes to the company's app-store policies, and has said it intends to appeal the judge's decision.

Adding the two together, a worst-case scenario where the U.S.-related Google payment and app-store fees drop to zero would take out around 20% of Apple's earnings per share. In that case, Daryanani sees the stock dropping to $144. Apple shares were down 1.2% at $208.78 on Monday.

Importantly however, that is not the Evercore analyst's base-case scenario. He kept a Buy rating on Apple stock with a $250 target price, on the assumption the eventual outcomes won't be as strict as threatened.

"We do think investors have become notably negative on Apple and should we see any of the court cases or tariff issues go Apple's way (or be less bad) that could be a sizable positive for the stock," Daryanani wrote.