The home of Santander Bank’s 46,350-square-foot offices and retail branch at 515 Massachusetts Ave. in Cambridge was acquired last week for $30.1 million.

The buyer is Parteen LLC of Boston, according to the Suffolk County Registry of Deeds, with an $18-million mortgage from First Republic Bank.

The price is $649 per square foot. Newmark Knight Frank Executive Managing Director Geoffrey Millerd, Managing Director Justin Smith, Associate Director Paul Penman and Financial Analyst Christian Brannelly of Newmark Knight Frank’s Boston Capital Markets Group led by U.S. Head of Capital Markets Robert Griffin represented seller S-BNK Cambridge LLC.

S-BNK Cambridge LLC paid $10.9 million for the property in 2000, according to data from The Warren Group, publisher of Banker & Tradesman.

Santander leases the entire building located next-door to MIT’s “Engine” makerspace.

“The influx of national retail tenants such as Target and Caffè Nero, plus the arrival of high-end restaurants such as Little Donkey and Waypoint, have been great for the Central Square market,” Newmark Knight Frank’s Penman said in a statement.

The site also has potential for future development under recent rezoning, Newmark said.