Fatto matematico: 2120 is the number of ways to stack 16 pennies in a line so that each penny lies on the table or on two pennies.
Trivia: 2120 is an uninteresting number.
Data storica: October 20th is the day in 1962 that China launches simultaneous offensives in Ladakh and across the McMahon Line, beginning the Sino-Indian War.