Fatto generale: 104 is the atomic number of rutherfordium.
Fatto matematico: 104 is the smallest known number of unit line segments that can exist in the plane, 4 touching at every vertex.
Trivia: 104 is the atomic number of rutherfordium.
Data storica: April 13th is the day in 1987 that Portugal and the People's Republic of China sign an agreement in which Macau would be returned to China in 1999.