Fatto generale: 189 is the atomic number of an element temporarily called Unoctennium.
Fatto matematico: 189 is a Kaprekar constant in base 2.
Trivia: 189 is the rank of Brazil in population density.
Data storica: July 7th is the day in 1954 that Elvis Presley made his radio debut when WHBQ Memphis played his first recording for Sun Records, "That's All Right.