Lawrence H. Summers plays down his stint in the hedge fund business as a mere part-time job  but the financial and intellectual rewards that he gained there would make even most full-time workers envious.

Mr. Summers, the former Treasury secretary and Harvard president who is now the chief economic adviser to President Obama, earned nearly $5.2 million in just the last of his two years at one of the world’s largest funds, according to financial records released Friday by the White House.

Impressive as that might sound, it is all the more considering that Mr. Summers worked there just one day a week.

Much is known about Mr. Summers’s days in Washington and Cambridge, but little attention has been paid to his two years in New York, from late 2006 to late 2008, advising an elite corps of math wizards and scientists devising investment strategies for D. E. Shaw & Company.