AS TENDS TO HAPPEN in journalism, numbers like these, especially big, round numbers, sooner or later get standardized. A consensus sets in.

The Times/Fascell $60 billion was clearly an overreach. It has never been repeated. Throughout the Seventies, the Mitchell figure of $50 billion settled in as the standard for political oratory, journalism and even academic writings on organized crime. Since 1970, judging from this past year's run of Mafia stories, the Mob's revenues have been barely touched by inflation.

Last summer's Time cover story on the Mob reports: "Estimates culled from a variety of law enforcement agencies suggest the Mafia takes in at least $48 billion in gross revenues and an incredible $20 billion or so in untaxed profits."

Jack Anderson's sources for an article on the same topic last year could not have agreed more: "Today the Mafia controls an underworld empire that takes in at least $48 billion a year, of which more than half is untaxed profits."

Both Time and Anderson write admiringly of a report by the government's high priesthood of the auditing profession, the General Accounting Office, which states: "Although exact figures are not available, the Department of Justice estimates that organized crime derives as much as $50 billion a year from gambling in addition to income from narcotics and loan sharking."

Since Anderson and Time compute $48 billion a year from all sources while Justice, as quoted by GAO, counts "as much as $50 billion" from gambling alone, Justice appears far in front of such conservative estimators as Anderson and Time. Add the appropriate figures for narcotics, loan-sharking, Teamster pension funds and gangland's "legitimate" ancillaries, and one could easily fantasize a $100-billion yearly gross for the 5,000 "made" Mafiosi and the 50,000 auxiliaries who are also part of the numerical mythology of Mafio-journalism.

When confronted with all the sources citing it, however, the Department of Justice went limp. A spokesman for the criminal division, after hunting around the department for a week, could not find any source for the $50 billion figure in the GAO report until somebody turned up a 10-year-old report by a Johnson-era task force on organized crime.

On page 3 of that report you do find the $50 billion figure. This is how you find it: "There is no accurate way of ascertaining organized crime's gross revenue from gambling in the United States. Estimates of the annual take have varied from $7 billion to $50 billion." It does not totally violate truth to paraphrase this as "as much as $50 billion," but the figures are for estimates (sources not identified) other than the Justice Department's and in a context clearly meant to disparage, not endorse, such estimates.

Whether you take the GAO/Johnson task force's $50 billion maximum for gambling alone or the Time/Anderson $48 billion for total mob enterprise, all four authorities draw the opposite conclusion from what you might expect.

After all, seven years ago a U.S. attorney general put the gross for organized crime at $50 billion. Since then the value of the dollar has shrunk by over a third. Merely to keep pace with the cost of living, the Mafia would have had to boost its gross receipts to $75 billion or so. Instead, it is either mired at $50 billion (GAO) or has actually slipped to $48 billion (Time/Anderson). Yet all three see organized crime not as a victim of creeping stagflation but very much on the rise: "Big, Bad and Booming" (Time); "The war on organized crime is faltering" (GAO); "The Federal Heat on Organized Crime is Subsiding" (Anderson).

And, even in inflated 1978 dollars, the $48-to-$50-billion Mafia gross, with its $25 billion in untaxed profits, prompts us to calculate with awe the take-home pay of Time's 55,000 made and unmade Mafiosi - presumably down to the thugs who break legs for the loan sharks. Average for the 55,000: a little under $500,000, a year, or just about par for a chairman of the board of - what else? - U.S. Steel.