  A number which is S.P in base r is a positive integer which is equal to the
sum of its base-r digits multiplied by the product of its base-r digits. These
numbers have been studied extensively in The Mathematical Gazette. Recently,
Shah Ali obtained the first effective bound on the sizes of S.P numbers.
Modifying Shah Ali's method, we obtain an improved bound on the number of
digits in a base-r S.P number. Our bound is the first sharp bound found for the
case r=2.
