The Number 391: Properties and MeaningsPrime Factors of 391=17x23.
391 is a Centered Pentagonal Number.
391 is a Centered 26-gonal Number.
391 is a Centered 39-gonal Number.
391 was a periodical created and edited by the Dadaist Francis Picabia.
The Year 391 ADIn the year 391 AD all non-Christian temples in the Empire were closed, as Theodosius established Christianity as the official state religion.
In the year 391 AD King Gwanggaeto the Great of Goguryeo ascended to the throne. (Korea).