TMZ Sports has learned ... the ex-Philadelphia Eagles player bought the insane Hollywood Hills home for his 31st birthday last month, and he even copped a vacant, 10,156-square-foot lot next to it as well.

We're told the price tag on it all was $6,325,000 ... and check out the pics of the place -- it appears to be worth every penny.

The hillside house -- which sits just moments away from the iconic Sunset Strip -- offers an incredible view of the L.A. skyline from the hills to Downtown L.A.

The dope pad features four bedrooms and five bathrooms and over 5,900 square feet ... as well as a primary bed suite with a sitting area and balcony that overlooks city lights.

There's more -- the crib also comes with three additional guest suites and features large closets and en suite bathrooms ... as well as a massive kitchen fully equipped with state-of-the-art appliances.

Brooke A. Elliott of Aaron Kirman Group at Compass represented the seller, while Kennon Earl of Rare Properties at Compass represented Acho.

As for Acho's feelings on the sale, he's clearly pleased with it all ... posting from the pad last month, "I didn't know what to do for my birthday... #NewHomeOwner #LosAngeles."