  A polynomial x^3+px^2+qx+r with the condition pr^(1/3)+ 3r^(2/3)+q=0 we call
a Ramanujan cubic polynomial (RCP). We study different interest properties of
RCP, in particular, an important role of a parameter pq/r. We prove some new
beautiful identities containing sums of 6 cubic radicals of values of
trigonometrical functions as well.
