Nitro, Nitroso, Nitrate, and Nitrite Compounds, Organic. Reactive groups are categories of chemicals that typically react in similar ways because they are similar in their chemical structure. Each substance with a chemical datasheet has been assigned to one or more reactive groups, and CAMEO Chemicals uses the reactive group assignments to make its reactivity predictions.
The largest  number that has a commonly-known specific name is a googolplex,  which is a 1 followed by a googol zeros, where googol is 10100 (a 1  followed by 100 zeros).
Whilst infinity is the largest theoretical number in the world, the largest number that could be written down would be only 10^10^87 since there are only 10^87 elementary particles in the whole universe.