June 28 - A "Perfect" Day

On the only date in the year for which the day number and the month number are both perfect numbers.
A perfect number is a positive integer that equals the sum of its proper divisors (divisors excluding the number itself).
 

June is the 6th month. it's divisors are 2, 3 and 1 (2x3x1=6). Add those together and it's 2+3+1=6.
The 28th day: Divisors of 28 are 14, 7, 4, 2 and 1. Add those and it equals 28.
??

If you include 1 as a divisor of 6, shouldn't you also include 6?

If you include 1 as a divisor of 28, shouldn't you also include 28?
 
June is the 6th month. it's divisors are 2, 3 and 1 (2x3x1=6). Add those together and it's 2+3+1=6.
The 28th day: Divisors of 28 are 14, 7, 4, 2 and 1. Add those and it equals 28.
Well this certainly is an odd formulation. Normally such mathematical little gems rely on prime numbers only. But OK it makes for a cute little thread! :cool:
 


Back
Top