This number is a prime.
The digits of 4561 (abcd) produce a distinct nine-digit product in the following expression: (a+b+c+d)(ab+cd)(a+bcd)(abc+d). [Meller]
Oprah Winfrey's show, highest-rated talk show in the history of American television, ended on 25 May 2011 after 25 years and 4561 episodes. [Post]