The MacArthur Foundation, which is best known for its no-strings grants to creative "geniuses," announced yesterday that it will donate $25 million for scholarly research and education dealing with "the threat of nuclear annihilation."

Most of the money, to be disbursed over the next three years, will go to private think tanks and universities for "international security studies," focusing on United States-Soviet relations and disarmament.

However, the largest single grant, $6.24 million, will be for an open world-wide competition for individual scholars on issues of "superpower behavior and nuclear danger." The foundation said 32 two- and three-year fellowships will be awarded each year for the next three years. The program will be run by the Social Science Research Council of New York.

Jerome B. Wiesner, a member of the MacArthur Foundation board who made the announcement at a press conference in the National Press Club, said the donations were aimed at reducing "the knowledge gap between what we understand now and what we needed to know to save the planet from extinction."

Wiesner, 69, retired as president of the Massachusetts Institute of Technology in 1980 and has been a strong advocate of reduced American military spending and disarmament. He served as science adviser to Presidents Kennedy and Johnson.

"In a world capable of almost instant self-destruction, we must rethink our options," Wiesner continued, "and discover new strategies that will insure a safer and more secure world."

Grant recipients in the Washington area include the Brookings Institution, $1.95 million, the second-largest recipient in the program; The Federation of American Scientists Fund, the Center for Strategic and International Studies of Georgetown University, and the University of Maryland, $300,000 apiece; and the Arms Control Association, the Committee for National Security, and the Woodrow Wilson International Center for Scholars, $150,000 each.

Five universities will receive $750,000 apiece: Columbia, Harvard, Stanford, M.I.T., and the University of California at Berkeley.

Wiesner said that despite his own strong views on disarmament, the grants would be "nonpartisan." He said the institutions would "decide how these resources will be used" without having to get specific proposals approved by the foundation.

However, Edward N. Luttwak, a senior fellow at the Georgetown Center who is a leading advocate of increased U.S. military strength, said much of the money seems meant for "propaganda for arms control" or is going to "purely political organizations."

Luttwak added: "Then they seem to be trying to balance the ticket by giving some grants to large and serious institutions. This seems to be a case of tax-protected money being handed out in a reckless way."

The MacArthur Foundation, with about $2 billion in assets, is the second-largest nonprofit foundation in the United States, after the Ford Foundation. It has expanded rapidly in the past six years with assets willed by its founder, John D. MacArthur, the owner of Bankers Life and Casualty Co., who died in 1978. On Wednesday, the foundation announced that it would realize $500 million from the sale of properties in the New York City area, which experts said was the largest residential real-estate transaction ever in that region.

Wiesner said the foundation's international security grants would be directed by Ruth Adams, former editor of the Bulletin of the Atomic Scientists, a prodisarmament magazine.

In a press release, the foundation said its money "almost doubles yearly U.S. expenditures for independent research in the field of international security." But an official said that tabulation excludes larger research programs on foreign policy.