Fatto matematico: 810 is a value of n for which n-1 and n+1 are twin primes, and so are 2n-1 and 2n+1.
Trivia: 810 is an unremarkable number.
Data storica: March 20th is the day in 1951 that Fujiyoshida, a city located in Yamanashi Prefecture, Japan, in the center of the Japanese main island of Honshū is founded.