An ever-bigger slice of the world's budget is going to the military

The world is spending a total of $660,000,000,000 a year on arms. That's right: $660 with nine ciphers after it. This is according to the ninth annual report entitled ''World Military and Social Expenditures 1983,'' sponsored by the Rockefeller Foundation and other institutions.

Meanwhile, 2 billion of the world's 4.5 billion people live in poverty and 450 million suffer hunger and malnutrition.

Until 1974, federal estimates of global arms costs were made by the US Arms Control and Disarmament Agency. When the surveys were discontinued, Ruth -Leger Sivard, who compiled the statistics for the government, maintained the survey with Foundation support. Among this year's findings:

* The world's stockpile of nuclear weapons represents an explosive force more than 5,000 times greater than all the munitions used in World War II.

* The United States devotes more than $200 billion a year to military defense against foreign enemies.

* Among 20 developing countries with the largest foreign debts, arms imports between 1976 and 1980 were equivalent to 20 percent of the increase in debt in that period.

* While US farmers are paid to take nearly 100 million acres of land out of production, 450 million people in the world are described as ''starving.''

* The small Mideast nation of Oman has a gross national product (GNP) of $4. 78 billion and spends 24.8 percent of it on the military.

* The cost of a single nuclear submarine equals the annual education budget of 28 developing countries with 160 million school-age children.

* Debt-burdened governments buy guns rather than build schools. One result: 800 million of the earth's adults can't read or write.

Arms expenditures have leaped in the past few years, the study shows: ''In 1982, world military expenditures are an estimated $660 billion, indicating an increase of at least 13 times in the volume of military activity'' since the mid-1930s. It says ''this greatly exceeds the increase in population to be protected and in the economic base to support it.''

The study finds two factors pushing the arms increase: the impetus of the wartime growth of the military-industrial complex since World War II, and ''the acceptance by the public of a higher level of sacrifice to which war had accustomed them. Without organized and persistent public resistance, the military establishment created to meet the emergency tends to remain in place.''

The US and Soviet Union emerged from World War II as global superpowers: ''Representing no more than 11 percent of the world's population, they now accounted for over half of a greatly enlarged world military budget.''

The superpower role did not come cheaply to either country. ''At $855 per capita in 1982, military expenditures in the US compared with $75 in comparable prices just before World War II. . . . The military effort has risen faster than GNP, and the burden on the economy as a whole now stands at 6.5 percent as compared with 1 percent pre-war.''

The burden weighs heavier on the Soviet Union with a smaller GNP. ''In 1980, the annual economic product of the USSR was still less than half as big as the US GNP, and its military outlays took 10 to 12 percent of it.''

In a foreword to 48 pages of expenditure analysis, charts, and statistical tables, Frank von Hippel, chairman of the Federation of American Scientists, says that ''the search for security through technology has led to increased vulnerability.'' It has caused ''the growth of military-industrial establishments,'' he says.

Sponsors of the study include a Canadian and Swedish organization and the British Council of Churches.

Social neglect has gone hand in hand with arms buildup, according to statistical comparisons.

Life expectancies are 21 years shorter in the poorest fifth of the world than among the richest fifth. Preparation for war kills people just as war itself does, the report argues.

The military now controls the governments of 52 or so of the world's developing countries. The present buildup of nuclear weapons now equals an explosive force of 3.5 tons of TNT for each person on earth.