**One hundred nine**(also

**One hundred and nine**) (109, CIX) is the natural number following one hundred eight and preceding one hundred ten. It is the 29nd prime number. The previous prime is one hundred seven, with which it comprises a twin prime.

**One hundred nine** is also:

- The atomic number of meitnerium.
- The registry number of the famous patrol boat PT-109, commanded by John F. Kennedy.