The Number 217
217 is a 12-gonal Number.
217 is a Centered Hexagonal Number.
217 is a Centered 36-gonal Number.
The Year 217 ADIn the year 217 AD Caracalla, Roman Emperor was assasinated.
In the year 217 AD Macrinus, of Mauritania, became the first equestrian Roman Emperor.
In the year 217 AD Pope Callixtus I succeeded Pope Zephyrinus as the sixteenth pope.