/big'nuhm/
[orig. from MIT MacLISP]
n. 1. [techspeak] A multiple-precision computer representation for very large integers. More generally, any very large number. "Have you ever looked at the United States Budget? There's bignums for you!"
2. [Stanford] In backgammon, large numbers on the dice are called 'bignums', especially a roll of double fives or double sixes (compare moby, sense 4).
See also El Camino Bignum.
Sense 1 may require some explanation. Most computer languages provide a kind of data called 'integer', but such computer integers are usually very limited in size; usually they must be smaller than than 231 (2,147,483,648) or (on a losing bitty box) 215 (32,768). If you want to work with numbers larger than that, you have to use floating-point numbers, which are usually accurate to only six or seven decimal places. Computer languages that provide bignums can perform exact calculations on very large numbers, such as 1000! (the factorial of 1000, which is 1000 times 999 times 998 times ... times 2 times 1). For example, this value for 1000! was computed by the MacLISP system using bignums:
402387260077093773543702433923003985719374864210714632543799910429938512398629 020592044208486969404800479988610197196058631666872994808558901323829669944590 997424504087073759918823627727188732519779505950995276120874975462497043601418 278094646496291056393887437886487337119181045825783647849977012476632889835955 735432513185323958463075557409114262417474349347553428646576611667797396668820 291207379143853719588249808126867838374559731746136085379534524221586593201928 090878297308431392844403281231558611036976801357304216168747609675871348312025 478589320767169132448426236131412508780208000261683151027341827977704784635868 170164365024153691398281264810213092761244896359928705114964975419909342221566 832572080821333186116811553615836546984046708975602900950537616475847728421889679646244945160765353408198901385442487984959953319101723355556602139450399736 280750137837615307127761926849034352625200015888535147331611702103968175921510 907788019393178114194545257223865541461062892187960223838971476088506276862967 146674697562911234082439208160153780889893964518263243671616762179168909779911 903754031274622289988005195444414282012187361745992642956581746628302955570299 024324153181617210465832036786906117260158783520751516284225540265170483304226 143974286933061690897968482590125458327168226458066526769958652682272807075781 391858178889652208164348344825993266043367660176999612831860788386150279465955 131156552036093988180612138558600301435694527224206344631797460594682573103790 084024432438465657245014402821885252470935190620929023136493273497565513958720 559654228749774011413346962715422845862377387538230483865688976461927383814900 140767310446640259899490222221765904339901886018566526485061799702356193897017 860040811889729918311021171229845901641921068884387121855646124960798722908519 296819372388642614839657382291123125024186649353143970137428531926649875337218 940694281434118520158014123344828015051399694290153483077644569099073152433278 288269864602789864321139083506217095002597389863554277196742822248757586765752 344220207573630569498825087968928162753848863396909959826280956121450994871701 244516461260379029309120889086942028510640182154399457156805941872748998094254 742173582401063677404595741785160829230135358081840096996372524230560855903700 624271243416909004153690105933983835777939410970027753472000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000