一个数如果恰好等于它的因子之和，这个数就称为“完数”。例如6=1＋2＋3.编程 　　　找出1000以内的所有完数。 -A number of factors if it is exactly equal to the sum of this number is called " End of a few." For example, 6 = 1+2+3. Programmatically find all finished within a few 1000.