(6*6*6) = 47 is the only prime number p such that the
sum of the digits of 666p is
equal to 666. If we define S(n) as the sum of the digits of
n, we can write that
S(666(6*6*6)) = 666. [Capelle]
Submitted: 2005-06-26 06:52:40; Last Modified: 2008-01-30 11:28:00.