What is another word for one-quintillionth?
Pronunciation: [wˈɒnkwˈɪntɪlˌi͡ənθ] (IPA) 
One-quintillionth is an incredibly small fraction, representing one part out of 1,000,000,000,000,000,000. It is hard to imagine something so infinitesimal, and it's no wonder that synonyms for the word are few and far between. However, there are a few ways to express the same concept, including "one-thousandth of one-sextillionth," "one-billionth of one-quadrillionth," and "one-trillionth of one-quintillionth." Each of these phrases refers to the same incredibly small fraction, and they can be useful for scientific or engineering calculations. Regardless of the wording used, it's clear that one-quintillionth is a minuscule portion that is difficult to grasp.
