Octillion is an astronomical number that represents 1 followed by 27 zeros. Although there are not that many synonyms for Octillion, some terms that can be used to represent such a magnanimous number are centillion, nonacentillion or decillions. These words are used to describe numbers that are extremely large and cannot be imagined with ease. Centillion represents 1 followed by 303 zeros, while nonacentillion signifies 1 followed by 309 zeros, and finally, decillion is used to represent 1 followed by 33 zeros. All of these numbers are so large that it becomes quite challenging to understand their magnitude in terms of the real world.