Fatto matematico: 2196 is the only number n so that 2n, 3n, 7n, and 9n together contain every digit 1-9 exactly twice.
Trivia: 2196 is an unremarkable number.
Data storica: January 4th is the day in 1972 that Rose Heilbron becomes the first female judge to sit at the Old Bailey in London, England, United Kingdom.