Prefix     value    symbol   example        etymology

Yotta      10^24    Y        Yottajoule     from otto, eight italian
Zetta      10^21    Z        Zettamole      from sette, seven italian
Exa        10^18    E        Exaweber       from hex, six in Greek
Peta       10^15    P        PetaHertz      from pente, five in Greek
Tera       10^12    T        Teracandela    teras, monster in Greek
Giga       10^9     G        Gigawatt       gigas, giant in Greek
Mega       10^6     M        Megakelvin     megas, huge in Greek
kilo       10^3     k        kilovolt       khilioi, thousand in Greek
hecto      10^2     h        hectoradian    hekaton, hundred in Greek
Deca/Deka  10       D        Dekapascal     deka, ten in Greek
deci       10^-1    d        decisievert    decimus, tenth in Latin
centi      10^-2    c        centimetre     centum, hundred in Latin
milli      10^-3    m        milliampere    mille, thousand in Latin
micro      10^-6    mu       microohm       mikros, small in Greek
nano       10^-9    n        nanosecond     nanos, dwarf in Greek
pico       10^-12   p        picofarad      pico, little bit in Spanish
femto      10^-15   f        femtonewton    femten, 15 in Danish or Norwegian
atto       10^-18   a        attogram       atten, 18 in Danish or Norwegian
zepto      10^-21   z        zeptohenri     from sept, seven Greek 
yocto      10^-24   y        yoctolitre     from okto, eight Greek