For centuries, the number 13 has been associated with bad luck, especially if it falls on a Friday. Here are ten interesting facts about the origins and events related to this sinister prime:

1. Fear of the number 13 even has a name. It’s called triskaidekaphobia. Specific fear of Friday the 13th is referred to as friggatriskaidekaphobia. People suffering from these irrational fears can get treatment at the Friggatriskaidekaphobia Treatment Center in Pocopson, Pennsylvania. Treatment includes clever games, costumed hosts, anti-superstition music, and free educational literature.

2. Our fear of the number can be traced back to a biblical claim that if thirteen people share a meal at the same table, one of the diners will die within the year. Famous example: Jesus shared a meal with twelve of his disciples at the Last Supper.

3. Many people have an aversion to the number 13, including famous horror writer Stephen King. In 1984, King admitted to stepping over the 13th stair, feeling uncomfortable watching channel 13, and refusing to pause on page 13 while reading books. He included pages with digits that added up to 13, like page 85. He admitted, “It’s neurotic, sure. But it’s also safer.”

4. Several serial killers have 13-letter names, including Charles Manson, Jeffrey Dahmer, Theodore Bundy, Jack the Ripper, and Albert DeSalvo. So does Adolfus Hitler, which was Adolf Hitler’s baptismal name.

5. In some Spanish-speaking countries, Tuesday the 13th is considered bad luck. Tuesday is feared because it is the day of the week associated with Mars, the Roman god of war. The movie Friday the 13th was translated into Martes Tres (Tuesday the 13th) for its global release.

6. Taylor Swift considers 13 to be her lucky number. She was born on the 13th and turned 13 on Friday the 13th. Her first album went gold in 13 weeks, and her first #1 song had a 13-second introduction. Each time Taylor has won an award, she has sat in either the 13th row, 13th seat, 13th section, or row M, which is the thirteenth letter.

7. The following celebrities were born on Friday the 13th: Julia Louis-Dreyfus, Christopher Plummer, Kate Walsh, Frances Conroy, Steve Buscemi, Mary-Kate and Ashley Olsen. Born on an unlucky day hasn’t hampered their careers.

8. In 1882, Captain William Fowler founded the 13 Club of New York, a secret supper club that continued its meetings throughout the late 1800s and early 1900s. Its first meeting included 13 courses, was lit by 13 candles, and was attended by 13 people. Members performed unlucky feats such as passing under a ladder and tipping over salt containers on the table. Honorary members included Presidents Chester A Arthur, Grover Cleveland, Benjamin Harrison, and Theodore Roosevelt.

9. An alleged occurrence…Mark Twain was once invited as the 13th guest at a dinner party. He went, despite a friend’s warning. Later, Twain reported, “It was bad luck. They only had food for 12.”

10. Motorcyclists gather each Friday the 13th in Port Dover, Ontario (Canada) for rallies that draw thousands of participants. Described as “the biggest single-day motorcycle event in the world,” its summer attendance exceeds 100,000 bikers. This tradition dates back to 1981.