Fatto generale: 15053 is a number for which we're missing a fact (submit one to numbersapi at google mail!).
Fatto matematico: 15053 is a boring number.
Trivia: 15053 is a boring number.
Data storica: March 18th is the day in 1965 that Cosmonaut Aleksei Leonov, leaving his spacecraft Voskhod 2 for 12 minutes, becomes the first person to walk in space.