The International System of Units prefixes

PrefixSymbol1000m   10n   DecimalShort scaleLong scale
yottaY100081024 1000000000000000000000000SeptillionQuadrillion
zettaZ100071021 1000000000000000000000SextillionTrilliard
exaE100061018 1000000000000000000QuintillionTrillion
petaP100051015 1000000000000000QuadrillionBilliard
teraT100041012 1000000000000TrillionBillion
gigaG10003109 1000000000BillionMilliard
megaM10002106 1000000Million
kilok10001103 1000Thousand
hectoh10002/3102 100Hundred
decada10001/3101 10Ten
10000100 1One
decid1000-1/310-1 0.1Tenth
centic1000-2/310-2 0.01Hundredth
millim1000-110-3 0.001Thousandth
microμ1000-210-6 0.000001Millionth
nanon1000-310-9 0.000000001BillionthMilliardth
picop1000-410-12 0.000000000001TrillionthBillionth
femtof1000-510-15 0.000000000000001QuadrillionthBilliardth
attoa1000-610-18 0.000000000000000001QuintillionthTrillionth
zeptoz1000-710-21 0.000000000000000000001SextillionthTrilliardth
yoctoy1000-810-24 0.000000000000000000000001SeptillionthQuadrillionth