To name actual numbers from the above table the digits are grouped into threes, each group of three is named, and separated with decreasing powers of a thousand. The groups are named by writing the first digit, if it exists, then hundred and then the name of the multiple of ten twenty followed by the last digit three. The separators should be replaced from right to left with increasing powers of a thousand, million, billion… For example becomes one hundred and twenty three million four hundred and fifty six thousand seven hundred and eighty nine. Due to the impractical length of numbers such as this it is uncommon to find numbers given to more than a few degrees of precision in this form, more often they are simply written using Arabic numerals. It should also be noted that if any of the groups is zero, then it is not stated, and an "and" is only included for terms less than one hundred. For example one million and one, and one million one thousand and five are both correct.
Depending on whether you are using the old European system of powers of a million, or the more current system of powers of a thousand, then the name of a number can be created by extracting the name of the power from this table and then adding -illion to the end. This method should be treated with caution and it is common to find slight spelling variations, normally to aid with the pronunciation of the resulting word. In most situations it is preferable to write numbers such as these using standard form instead of words.
For an example of how this might work consider . This can be written as using the modern system. This is then interpreted as ducenti-quinquaginta-quattor-illion using the above table. The hyphens are normally removed leaving one ducentiquinquagintaquattorillion. In the older system it would be written as and interpreted as one centivigintiseptillion, noting that the e from septe has been ellided.
UM — How Many? A Dictionary of Units of Measures, published by Russ Rowlett and the University of North Carolina at Chapel Hill, online, accessed 1 April 2007.
milliard a unit of quantity equal to 109, which is what Americans call a billion.
billiard unit of quantity equal to 1015, which is one quadrillion in American terminology or 1000 billion in traditional British terminology. The name is coined to parallel milliard, which has long been a name for 1000 million.
trilliard a unit of quantity equal to 1021, which is one sextillion in American terminology or 1000 trillion in traditional British terminology. The name is coined to parallel milliard, which has long been a name for 1000 million.