Of all the number-crunching organizations in Washington, the Greater Washington Research Center may crunch the most numbers about Washington.

On issues ranging from the Baby Boom to the Beltway, the center has earned a reputation as the area's most comprehensive research group. And the economic and demographic trends it uncovers are often surprising, some Washingtonians said. Among its findings:

* Nearly half of the area's blacks live in the suburbs.

* Nearly half of the total labor force in the greater Washington area is female.

* Only one in three suburban workers commutes to the District.

Founded in 1958 and reorganized in 1978, the nonprofit center has conducted hundreds of studies on issues affecting the Washington area, providing a barometer of the growth and development of the area's labor force, financial services and emerging economy.

"They provide a very valuable service," said Prince George's county executive Parris N. Glendening. "In particular, they fill a void by promoting studies that other research organizations haven't really touched."

"They act as a check against our own thinking and planning," added Montgomery County executive Charles W. Gilchrist. "Sometimes we agree with them. Sometimes we don't. But they raise issues that are useful and helpful to our planning processes."

The center, whose budget this year is about $412,000, is funded primarily by contributions from corporations, charitable organizations and foundations.

Two major contributors are the Ford Foundation and Eugene & Agnes E. Meyer Foundation, which give additional funds for the center's special projects. The Meyer Foundation, for example, contributed an additional $60,000 to the center in the current funding year.

About 165 mostly local organizations belong to the center, including law firms, banks, accounting firms, hotels, department stores, utilities and construction companies.

Annual membership dues range from $550 to $2,200, depending on the size of the group. Founding members that still contribute to the center include Riggs National Bank, American Security Bank, Washington Gas Light Co., Potomac Electric Power Co., C&P Telephone Co. and IBM Corp., officials of the center said.

The center, which does no direct advocacy or lobbying, is wrapping up last year's special project, "The Third State of The Region Report," a biennial effort that will analyze the local economy. Robert S. McNamara, former secretary of Defense and head of the World Bank, headed the task force for the center's second state of the region report in 1982 on local government's response to fiscal pressure.

The center, whose chairman is R. Robert Linowes of Linowes & Blocher, has only six full-time employes. Most of the studies are contracted out to scholars such as Stephen S. Fuller of George Washington University, Harry P. Hatry of the Urban Institute and Thierry J. Noyelle from Columbia University.

"We made a conscious decision in 1978 to remain small," explained Atlee E. Shidler, the center's president. "If we engage in projects that go beyond our resources, we find other scholars who have a particular expertise."

The Better Babies project, a major effort undertaken by the center last year, was one in which the group did more than just conduct the study on infant mortality and make recommendations on how to reduce the number of low-weight babies: It helped find agencies to administer its suggestions. Under the guidance of the National Institute of Child Health and Development, the project is now being completed.

"I don't think any other research organization addresses the Washington area," said Roger R. Blunt of Blunt Enterprises Inc., who is president-elect of the Greater Washington Board of Trade. "I don't think any other organization has been addressing the area in the same way."

"To attract business to this region, one has to understand the area's demography, incomes, economy and employment trends," Blunt added.

Start-up grants from the Meyer Foundation and the Ford Foundation launched the original center, then called the Washington Center for Metropolitan Studies, in 1959. The founders were a group led by Frederick Gutheim, who had been staff director of the Joint Congressional Committee on Metropolitan Washington Problems during the preceding three years.

The founding group was concerned that no systematic research was being done on Washington's rapidly developing economy, local government, demography or particular problems. Originally, the group envisioned a collective university-based institution, but the center has never been formally tied to universities. The center's volume of reports makes it seem as if numbers on every imaginable area subject have been collected. But, Shidler said, there are several topics, such as international business and foreign tourism, that the center has not yet touched.

"We've got to grow up to the fact that we're becoming much more of an international city than ever before," Shidler said.