Perfect number

A perfect number is ... http://en.wikipedia.org/wiki/Perfect_number

6, 28, 496, 8128, 33550336, 8589869056, 137438691328, 2305843008139952128, 2658455991569831744654692615953842176, 191561942608236107294793378084303638130997321548169216

http://oeis.org/A000396

Question :

Show that any even perfect number greater than 28 can be represented as the sum of at least two perfect numbers.