Great Site: What’s Special About This Number?

Last week, I stumbled on this fun site. It’s a running list of numbers with an indication about what is special about that number.

Stuff like …

• 2 is the only even prime
• 6 is the smallest perfect number
• 8 is the largest cube in the Fibonacci sequence

and just a few of my favorites from the first 100

• 40 is the only number whose letters are in alphabetical order
• 53 is the only two digit number that is reversed in hexadecimal
• 67 is the smallest number which is palindromic in bases 5 and 6
• 77 is the largest number that cannot be written as a sum of distinct numbers whose reciprocals sum to 1

The site is also full of links to fun and interesting math topics – if you find math fun and interesting.