The etymology of the SI prefixes is quite interesting in itself.  Many came from Greek and Latin via the French but a few are from other European languages.  The choice of femto was convenient because fm for 10^-15 metres coincides with the old symbol which was short for fermi.  Peta and exa were apparently modelled on tera by imagining that it came from tetra (four in Greek) with the r dropped.  Hence peta is penta with the n dropped and exa is hexa with the h dropped.  In the cases of yotta, zetta, zepto and yocto the initial letters were obviously required because they would not confuse with other symbols.  Other than that they are roughly modelled on previous prefixes.

http://math.ucr.edu/home/baez/physics/Administrivia/notation.html

 Each prefix is represented by it's own symbol. The symbols are case sensitive. Thus, m means milli and M means mega.

Prefixes ranging from micro to mega were first introduced in 1874 by BAAS as part of their CGS system. Later, 12 prefixes ranging from pico to tera were defined as part of the International System of Units - SI, which was adopted in 1960. SI is maintained by BIPM under exclusive supervision of CIPM and resolutions made by CGPM. Further 8 prefixes were added to SI in years 1964 (femto, atto), 1975 (peta, exa) and 1991 (zetta, zepto, yotta, yocto).

The prefixes have the following etymology:

• exa: alteration of hexa from Greek hex meaning "six" (the sixth power of 10³)

• peta: alteration of penta from Greek pente meaning "five" (the fifth power of 10³)

• tera: from Greek teras meaning "monster"

• giga: from Greek gigas meaning "giant"

• mega: from Greek megas meaning "great"

• kilo: from Greek khilioi meaning "thousand"

• hecto: French, alteration of Greek hekaton meaning "hundred"

• deca: from Greek deka meaning "ten"

• deci: from Latin decimus meaning tenth, from decem meaning "ten"

• centi: from Latin centi-, from centum meaning "hundred"

• milli: from Latin mille meaning "thousand"

• micro: from Greek mikros meaning "small"

• nano: from Greek nannos meaning "dwarf"

• pico: from Spanish pico meaning "small quantity"

• femto: from Danish, or Norwegian word femten meaning "fifteen"

• atto: from Danish, or Norwegian word atten meaning "eighteen"

 The names zepto and zetta are derived from septo, from Latin septem which means seven (the seventh power of 10³) and the letter 'z' is substituted for the letter 's' to avoid the duplicate use of the letter 's' as a symbol in SI. The names yocto and yotta are derived from Latin octo which means eight (the eighth power of 10³); the letter 'y' is added to avoid the use of the letter 'o' as a symbol because it may be confused with the number zero. The CGMP has decided to name the prefixes, starting with the seventh, with the letters of the Latin alphabet, but starting from the end. Therefore the choice of letters 'z' and 'y'. The initial letter 'h' of the word hexa in standard French is silent, so it was removed in order to simplify things.

http://members.optus.net/alexey/prefSI.html

http://home.att.net/~numericana/answer/humor.htm#units

also see:

http://www.w-akten.de/statistik.shtml
http://www.computerhope.com/jargon/z/zepto.htm
http://www.friesian.com/quanta.htm#note
http://www.cs.unb.ca/~alopez-o/math-faq/mathtext/node25.html

some more ...

>6 Million
>9 Milliarde
>12 Billion
>15 Billiarde
>18 Trillion
>21 Trilliarde
>24 Quadrillion
>27 Quadrilliarde
>30 Quintillion
>33 Quintilliarde
>36 Sextillion
>39 Sextilliarde
>42 Septillion
>45 Septilliarde
>48 Octillion
>51 Octilliarde
>54 Nintillion
>57 Nintilliarde
>60 Decillion
>63 Decilliarde
>66 Undecillion
>69 Undecilliarde
>72 Duodecillion
>75 Duodecilliarde
>78 Tredecillion
>81 Tredecilliarde
usw.

Quattuordecillion mit 84 nullen,
Quindecillion = 90 Nullen
sexdecillion = 96 Nullen
septendecillion = 102 nullen
octodecillion = 108 Nullen
novemdecillion = 114 Nullen
Vigintillion = 120 Nullen
Trigintillion = 180 Nullen
Quadragintillion = 240 Nullen
Quinquagintillion = 300 Nullen
Sexagintillion = 360 Nullen
Septuagintillion = 420 Nullen
Octogintillion = 480 Nullen,
Nonagintillion = 540 Nullen
Centillion = 600 Nullen
Ducentillion = 1.200 Nullen
Trecentillion = 1.800 Nullen
Quadringentillion = 2.400 Nullen
Quingentillion = 3.000 Nullen
Sescentillion = 3.600 Nullen
Septingentillion = 4.200 Nullen
Octingentillion = 4.800 Nullen
Nongentillion = 5.400 Nullen
Milliatillion = 6.000 Nullen
Domilliatillion = 12.000 Nullen
Tremilliatillion = 18.000 Nullen

 und das geht dann unter anderem noch bis zur Milliamilliatrecentunquinquaginmilliacentnovemquadragintillion usw.

http://www.f1.parsimony.net/forum1924/messages/105.htm

http://www.unc.edu/~rowlett/units/large.html

How Many? A Dictionary of Units of Measurement
© Russ Rowlett and the University of North Carolina at Chapel HillNames for Large Numbers

The English names for large numbers are coined from the Latin names for small numbers n by adding the ending -illion suggested by the name "million." Thus billion and trillion are coined from the Latin prefixes bi- (n = 2) and tri- (n = 3), respectively. In the American system for naming large numbers, the name coined from the Latin number n applies to the number 10³ⁿ⁺³. In a system traditional in many European countries, the same name applies to the number 10⁶ⁿ.

In particular, a billion is 10⁹ = 1 000 000 000 in the American system and 10¹² = 1 000 000 000 000 in the European system. For 10⁹, Europeans say "thousand million" or "milliard."

Although we describe the two systems today as American or European, both systems are actually of French origin. The French physician and mathematician Nicolas Chuquet (1445-1488) apparently coined the words byllion and tryllion and used them to represent 10¹² and 10¹⁸, respectively, thus establishing what we now think of as the "European" system. However, it was also French mathematicians of the 1600's who used billion and trillion for 10⁹ and 10¹², respectively. This usage became common in France and in America, while the original Chuquet nomenclature remained in use in Britain and Germany. The French decided in 1948 to revert to the Chuquet ("European") system, leaving the U.S. as the chief standard bearer for what then became clearly an American system.

In recent years, American usage has eroded the European system, particularly in Britain and to a lesser extent in other countries. This is primarily due to American finance, because Americans insist that $1 000 000 000 be called a billion dollars. In 1974, the government of Prime Minister Harold Wilson announced that henceforth "billion" would mean 10⁹ and not 10¹² in official British reports and statistics. The Times of London style guide now defines "billion" as "one thousand million, not a million million."

The result of all this is widespread confusion. Anyone who uses the words "billion" and "trillion" internationally should make clear which meaning of those words is intended. On the Internet, some sites outside the U.S. use the compound designation "milliard/billion" to designate the number 1 000 000 000. In science, the names of large numbers are usually avoided completely by using the appropriate SI prefixes. Thus 10⁹ bytes is a gigabyte and 10¹² joules is a terajoule. Such terms cannot be mistaken.

There is no real hope of resolving the controversy in favor of either system. Americans are not likely to adopt the European nomenclature, and Europeans will always regard the American system as an imposition. However, it is possible to imagine a solution: junk both Latin-based systems and move to a Greek-based system in which, for n > 3, the Greek number n is used to generate a name for 10³ⁿ. (The traditional names thousand and million are retained for n = 1 and 2 and the special name gillion, suggested by the SI prefix giga-, is proposed for n = 3.)

 This process can be continued indefinitely, but one has to stop somewhere. The name centillion (n = 100) has appeared in many dictionaries. A centillion is 10³⁰³ (1 followed by 303 zeroes) in the American system and a whopping 10⁶⁰⁰ (1 followed by 600 zeroes) in the European system.

 Finally, there is the googol, the number 10¹⁰⁰ (1 followed by 100 zeroes). Invented more for fun than for use, the googol lies outside the regular naming systems. The googol equals 10 duotrigintillion in the American system, 10 sexdecilliard in the European system, and 10 triacontatrillion in the proposed Greek-based system.

 The googolplex (1 followed by a googol of zeroes) is far larger than any of the numbers discussed here.

John Knoderer American Numbering System and Place Values:

http://www.mazes.com/AmericanNumberingSystem.html

http://www.kokogiak.com/megapenny/default.asp

Numerical Prefixes

 A prefix is a syllable at the beginning of a word. A numerical prefix lets you know how many there are of a particular thing. Here are some common numerical prefixes.

http://www.factmonster.com/ipka/A0774340.html