66 (number) facts for kids

Sixty-six is a number that comes right after sixty-five and before sixty-seven. It is an even number, which means you can divide it by two without any remainder. Sixty-six is also a composite number, because it has more than two factors (numbers that divide into it evenly). Its factors are 1, 2, 3, 6, 11, 22, 33, and 66.

What Kind of Number is 66?

Sixty-six has several interesting mathematical properties. It's not just a number on a number line; it's part of different number patterns.

Triangular Numbers

Sixty-six is a triangular number. Imagine arranging dots in the shape of a triangle. A triangular number is the total number of dots in such a shape. For example, 1 is a triangular number (one dot), 3 is a triangular number (three dots in a triangle), and so on. Sixty-six is the 11th triangular number. This means if you add up all the numbers from 1 to 11 (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 + 11), you get 66.

Hexagonal Numbers

Sixty-six is also a hexagonal number. These numbers represent the total number of dots needed to form a regular hexagon (a six-sided shape) with dots on its sides. The first hexagonal number is 1, the second is 6, the third is 15, and so on. Sixty-six is the 6th hexagonal number.

Other Math Facts

• Sixty-six is a sphenic number. This means it is the product of three different prime numbers. For 66, these prime numbers are 2, 3, and 11 (2 × 3 × 11 = 66).
• It is a perfect totient number. This is a special type of number related to how many numbers are less than it and share no common factors with it.
• Sixty-six is the largest number that has no prime factors larger than 11.

Sixty-Six in Real Life

The number 66 appears in many places, from famous roads to sports.

U.S. Route 66

Perhaps one of the most famous uses of the number 66 is U.S. Route 66. This historic highway in the United States was established in 1926. It stretched from Chicago, Illinois, all the way to Santa Monica, California, covering about 2,448 miles (3,940 kilometers). It became known as "The Main Street of America" or "The Mother Road."

Route 66 was very important for people traveling west, especially during the 1930s when many families moved to California. It helped small towns along its path grow and became a symbol of freedom and adventure. Even though it was officially removed from the U.S. Highway System in 1985, parts of it are still preserved as "Historic Route 66" and are popular for tourism.

In Sports

In ice hockey, the number 66 is famous because it was worn by Mario Lemieux, one of the greatest players of all time. He played for the Pittsburgh Penguins and is considered a legend in the sport.

In Culture

The number 66 also appears in various cultural references, sometimes in sayings or codes. For example, in some places, "66" might be used in slang or as part of a code, similar to how other numbers gain special meanings.

Images for kids

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  Route 66 sign