DSolve[Derivative[1][y][x] == (-18*x - 6*x^3 + x^6 - 18*x*y[x] + 9*x^4*y[x] + 27*x^2*y[x]^2 + 27*y[x]^3)/(27 + 9*x^2 + 27*y[x]),y[x],x]