You shall count only the prime ones, both have only 2 prime divisors. Then 60 would be of real use (and it has been used in the past[1]... and still is in angul

You shall count only the prime ones, both have only 2 prime divisors. Then 60 would be of real use (and it has been used in the past[1]... and still is in angular measurements with the famous 360 degrees) but it contains only 5 as extra prime divisor. [1]: http://en.wikipedia.org/wiki/Sexagesimal http://en.wikipedia.org/wiki/Sexagesimal