Let's be specific here.
Grand Piano weighs: Aprrox 252KG
Sun's weighs: 1.989E30 kg
Divide the Pianos weight by the sun's to see how many fit in.
$${\frac{{\mathtt{1\,989\,000\,000\,000\,000\,000\,000\,000\,000\,000}}}{{\mathtt{252}}}} = {\mathtt{7\,892\,857\,142\,857\,142\,857\,142\,857\,142.857\: \!142\: \!857\: \!142\: \!857\: \!1}}$$
Ha...This is it (Approx).