Billonésimo

Billonésimo is a Spanish word referring to the ordinal number that follows billionésimo. In the traditional short scale system of numbering, which is common in Spanish-speaking countries and the United States, a billion is 1,000,000,000,000, or 10^12. Therefore, billonésimo would represent the one trillionth part.

This concept is used in mathematics and science when dealing with extremely small quantities or when expressing a fraction of a very large number. For instance, if a quantity is divided into a trillion equal parts, one of those parts would be referred to as one billonésimo.

It is important to distinguish this from the long scale system, where a billion (or billiard) is 1,000,000,000,000,000,000, or 10^18. In that system, the term for the 10^12 position would be different. However, the short scale is more widely adopted for economic and scientific contexts globally, including in most Spanish-speaking nations.

The word is formed by combining "billon" (billion) with the suffix "-ésimo," which denotes an ordinal position. Its usage is relatively rare in everyday language, typically confined to specialized fields where such large numbers are relevant.