Laura Erickson's For the Birds

Thursday, November 3, 2011

Top Ten Reasons to Look Forward to Turning Sixty!

Laura Erickson
Note: because my birthday is on 11/11/11, this list actually has 11 reasons!

11. Senior rates at the theater!

10. Babe Ruth hit 60 home runs in 1927.

9. I like the song 60-Minute Man by Billy Ward and the Dominoes. And since the song was released in 1951, the song is 60 years old, too!

8. 60 is a Harshad number—that is, a number divisible by the sum of its digits in base 10 (6+0).

7. The Babylonian number system had a base of sixty, inherited from the Sumerian and Akkadian civilizations, and possibly motivated by the large number of divisors which 60 has. Our culture has inherited our clock and some geometrical artifacts from this system, which is why one hour has 60 minutes and one minute has 60 seconds.

6. Each angle of an equilateral triangle is 60 degrees.

5. 60 is the sum of twin primes (29+31) and the sum of four consecutive primes (11+13+17+19). It’s sandwiched between two primes (59 and 61). It’s the smallest number which is the sum of two odd primes in 6 ways.

4. The icosidodecahedron has 60 edges, all equivalent. Buckminsterfullerene C60 has 60 carbon atoms in each molecule, arranged in a truncated icosahedron.

3. 60 is a composite number and a highly composite number, with divisors 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, and 60. It’s also one of only 3 unitary perfect numbers within a human lifespan in years. (The first few unitary perfect numbers are 6, 60, 90, 87360, 146361946186458562560000.) It is also an excessive number with an abundance of 48. Being ten times a perfect number, 60 is a semiperfect number.

2. #60 on my lifelist was the Scarlet Tanager! (First seen on June 23, 1975, near Kalamazoo, Michigan.)

Scarlet Tanager

1. The sum of the digits in 11/11/11 equals the sum of the digits in 60!

Addendum: I just remembered another cool thing about the number 60—the coldest temperature ever recorded in Minnesota was -60 degrees F, on February 2, 1996, in Tower. It was much warmer in Duluth that night. Our thermometer only got down to -41.


  1. Well, this is probably the most unusual list of reasons to look forward to your birthday! I'm two years behind you, so I'll have to keep these thoughts in mind. Happy Birthday ahead of time!

  2. One year and a month behind you. Great post!