"Four" is Beyoncé's favorite number, for many reasons.
Beyoncé was born on Sept. 4. Her mother, Tina Knowles, was born on Jan. 4, and her husband, Jay Z, was born on Dec. 4. Jay Z and Beyoncé got married on April 4, 2008, and got matching "IV" tattoos on their ring fingers. In 2011, she released her fourth studio album, which was titled 4, and in 2012, she named her daughter Blue Ivy, a play on the Roman numeral four.