Greip is about 6 kilometres in diameter , and orbits Saturn at an average distance of 18,066,000 km in 906.556 days , at an inclination of 172.7 Â to the ecliptic ( 159.2 Â to Saturn 's equator ) , and with an eccentricity of 0.3735 . S\/2006 S 4 is about 6 kilometres in diameter , and orbits Saturn at an average distance of 18,066 Mm in 906.556 days , at an inclination of 172.7 Â to the ecliptic ( 159.2 Â to Saturn 's equator ) , in a retrograde direction and with an eccentricity of 0.3735 .