NATIONAL YELLOW PIG DAY

3 min. read
July 17, 2026

NATIONAL YELLOW PIG DAY

National Yellow Pig Day on July 17 honors the unique attributes of the number 17 and its significance to mathematics. We plan on explaining what a yellow pig and the number 17 have in common, too!

#NationalYellowPigDay

The yellow pig has very little to do with the number 17. In fact, the only reason today is called National Yellow Pig Day is because the two students who wanted to create a day for the number 17 needed a mascot. Enter the yellow pig.

6 Ways the Number 17 Matter

  1. The number 17 is a premium number in the arena of prime numbers. Add the first four prime numbers together, and 17 is their sum.

  2. The average school bus weighs 17 tons with passengers inside.

  3. Each of the following words has 17 letters: interdisciplinary telecommunication misinterpretation commercialization electrophotometer

  4. The atomic number of chlorine is 17.

  5. Pebble Beach has a specific road known as the 17 Mile Drive along the Monterey Peninsula in California. However, the exact length of the road is 16.78 miles.

  6. The 17th Amendment of the U.S. Constitution gave the citizens of the United States the right to elect their senators by popular vote. Before the states ratified the amendment on April 8, 1913, each state's' legislature would elect the senators to Congress.

Look for the not so random occurrence of the number 17. Look! Yellow pig!

HOW TO OBSERVE NATIONAL YELLOW PIG DAY

Brush up on your calculus and round up your yellow pigs. Look for the number 17. It's everywhere! We even have more ideas to help you celebrate:

  • See how many times you find the number 17 in the newspaper on July 17.

  • Do 17 jumping jacks.

  • Order a round of drinks for 17 people (you big spender, you).

  • Eat 17 spoonfuls of Peach Ice Cream.

  • Buy 17 lottery tickets.

  • Get 17 tattoos a number 17 tattoo.

  • Study the 17-year Cicada cycle. This happens every 17 years, 2024 being the most recent.

While you're celebrating, be sure to post on social media using #NationalYellowPigDay.

NATIONAL YELLOW PIG DAY HISTORY

Our research found National Pig Day originated sometime during the early 1960s. Two mathematicians by the name of Michael Spivak and David Kelly were analyzing the random properties of the number 17 and a mysterious yellow pig. It seems the process became excessive and professional. Kelly gave lectures and taught classes around Yellow Pig, and Spivak made publications in several mathematics texts. While not based upon it, Spivak does subtly reference the number 17 and Yellow Pig.