What’s bigger than a trillion? Bigger than a quadrillion? Can we give names for large numbers which are snappier than $2^{74,207,281}−1$? As we have found the need to use large numbers in our lives, various interesting systems have been proposed. Impress your friends with some of these!

## Extending million, billion, trillion…

An extension to ‘million, billion, trillion’ was proposed in John Conway and Richard Guy’s book, The Book of Numbers (not to be confused with the slightly older book sharing its name).

With the English language finally having settled on the traditionally American designation that 1 billion = 1 thousand million (thanks finance!), Conway & Guy extended the system that already exists up to $10^{30}$. They take the number $n$ occurring in $10^{3n+3}$:

$10^6$ | million | $n=1$ | $10^{21}$ | sextillion | $n=6$ | |

$10^9$ | billion | $n=2$ | $10^{24}$ | septillion | $n=7$ | |

$10^{12}$ | trillion | $n=3$ | $10^{27}$ | octillion | $n=8$ | |

$10^{15}$ | quadrillion | $n=4$ | $10^{30}$ | nonillion | $n=9$ | |

$10^{18}$ | quintillion | $n=5$ | $10^{33}$ | decillion | $n=10$ |

and use its Latin translation as a prefix for $n \geq 10$. So we get

- $n = 11$:
**undec**illion - $n = 18$:
**octodec**illion - $n = 25$:
**quinvigint**illion