Swig Equities announced Wednesday morning its purchase of 25 Broad Street in the Financial District. The 21-story, 540,000-square-foot former office building has 346 one-, two- and three-bedroom rentals. It also has around 21,400 square feet of retail and commercial space and 6,800 square feet of office space. Built in 1902, the city designated the building as a landmark in 2000. It was converted to residential in 1997. Swig Equities, one of Downtown’s biggest commercial landlords, said the purchase price was more than $200 million, and declined to say whether the building will be converted to condos. The firm’s president, Kent Swig, did say in a release that the building was bought in the belief that Lower Manhattan will become a 24-hour community again.