Numbers which have made it into the English language

-- sixty-four dollar question -- also $64 question
The critical question about a problem; a crucial issue.
[From a popular radio quiz show in the US in the 1940s which offered $64 as the largest prize. The first question had a prize of $1 and the prize total doubled with each successive question: $2, 4, 8, 16, 32, culminating in the $64 question. With inflation, this term is used in many variant forms, such as, "$64,000 question" and upwards.]
"'We still don't know if he's an enemy combatant,' Mr. Dunham said. 'That's the $64 question.'"
Katharine Q. Seelye; Appeals Court Again Hears Case of American Held Without Charges or Counsel; The New York Times; Oct 29, 2002.
"Now, the sixty-four million-dollar question. Need one have learned a second language to teach English as a second language?"
Cultural Imperialism and the English Language Teacher; The Korea Times (Seoul, South Korea); Feb 24, 2000.

-- 404
Consider this sentence: "He went to look for Adrianna in her office but got a 404."
Or this: "By the time I came back to my desk, my book had 404ed."
Anyone who has been on the Internet for more than a few days would immediately know what 404 means. It indicates someone or something missing, alluding to the error code that Web servers spit out when a page is not found. With our creative capacity to extend meanings of words, we use them in completely unrelated contexts. And that's one of the ways language grows.

-- 101
We use 101 to refer to something introductory or elementary on a topic
("Brad doesn't even know etiquette 101"), from the use of the number to identify the first course on a subject in a school or university.

-- 180 degree turn -- comes from geometry and refers to a complete reversal.
("The company went 180 degrees on its strategy").

-- 24/7
From the business world, there is 24/7, to indicate complete availability ("He attended the sick child 24/7") referring to the number of hours in a day and the number of days in a week).

-- eighty-six (verb transitive), also 86
1. To throw out; discard; reject.
2. To refuse to serve (a customer).
adjective
Sold-out (of an item).
noun
An undesirable customer, one who is denied service.
"He says the show will go on next month, though scheduling conflicts may move it to another hotel and the band may be eighty-sixed."
Zan Dubin; Clubs in and Around Orange County; The Los Angeles Times; Jun 19, 1997.
"David enlists the help of his friend Richard Lewis to buy a bracelet for his wife from a jewelry store that 86ed him."
Melanie McFarland; `Curb' Built on `Seinfeld' Legacy; The Seattle Times; Oct 13, 2000.

-- deep-six (verb transitive)
1. To throw overboard.
2. To discard or reject.
[From nautical slang deep-six (burial at sea), or from the allusion to the typical depth of a grave.]
"Second, the PRI holds the biggest bloc of seats in both legislative houses, and Fox's relentless condemnation of their governance during his presidential bid has strengthened their resolve to deep-six his agenda."
George W. Grayson; Fox May Need a Miracle From the Pope; The News (Mexico City, Mexico); Jul 26, 2002.
"Yet prominent critics of the protocol - notably economist William Pizer of Resources for the Future, a Washington think tank, and political scientist David G. Victor of the Council on Foreign Relations - have argued that the best response isn't to deep-six Kyoto but to add a safety valve."
George Musser; Climate of Uncertainty; Scientific American (New York); Oct 1, 2001.

-- twenty-twenty (adjective), also 20/20
1. Possessing or relating to perfect vision.
2. Having ability to see an issue clearly.
[From a method of testing visual acuity involving reading a chart of letters or symbols at 20 feet away.]
"As pundits of power go, Machiavelli was a prince. Ophthalmologically speaking, Ted Levitt's twenty-twenty vision into marketing myopia was farsighted. Saint Peter of Drucker, arguably this century's most influential management thinker, has probably inspired more effective executives than a Covey of business gurus."
Michael Schrage; Staying Smart; Brave New Work: Will Evolving Corporate Strategy Be Dar-win-win-ian?; Fortune (New York); Jun 21, 1999.
"With 20/20 hindsight, we see that our national unity problem was not so much a constitutional issue, and certainly not a racebased conflict, but merely the result of our cultural ignorance."
Benoit Aubin; Speaking in Tongues; Maclean's (Toronto, Canada); Dec 9, 2002.

-- catch-22 (noun)
A situation marked by contradiction, absurdity, or paradox, where a solution is impossible to achieve.
[From Catch-22, a novel by Joseph Heller.]
In this World War II novel, an air force regulation states that a man is to be considered insane if he is willing to continue to fly dangerous missions. To be relieved of such duties all he has to do is ask. But one who makes such a rational request shows that he is, in fact, sane. Here is an extract from the novel.
Doc Daneeka said, "He (Orr) has to be crazy to keep flying combat missions after all the close calls he's had. Sure I can ground Orr. But first he has to ask me to."
"That's all he has to do to be grounded?"
"That's all. Let him ask me."
"And then you can ground him?" Yossarian asked.
"No, then I can't ground him."
"You mean there's a catch?"
"Sure there is a catch," Doc Daneeka replied.
"Catch-22. Anyone who wants to get out of combat duty isn't really crazy."
"Yet ask members of the public what they think about street sellers, and the most virtuous will respond that they should be banned from the city streets. Yet the sellers do a roaring trade, and could not do so unless their goods and services met a substantial public need. Some solution to this Catch 22 situation is long overdue ..."
Word From the Streets: The Plight of the Informal Sector; The National (Papua New Guinea); May 19, 2003.
"The players involved say it's too early to talk about it, which leads to a catch-22. If you wait until it becomes a pertinent issue, it may no longer even be an issue."
Tony Jackson; Reds Ponder Rare Slugging Trio; Sebastian Sun (Florida); May 21, 2003.