Fatto generale: 1634 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 1634 is a narcissistic number.
Trivia: 1634 is an unremarkable number.
Data storica: June 21st is the day in 1900 that Baron Eduard Toll, leader of the Russian Polar Expedition of 1900, departed Saint Petersburg in Russia on the explorer ship Zarya, never to return.