No. There currently already is a Crown Prince to Greece, (Crown Prince Pavlos and his wife Crown Princess Marie-Chantal), and even if Prince Pavlos wasn't heir to the throne Prince Philip couldnt be King as he is the consort to another country.
Pavlos, Prince of Demark is 50 years old (birthdate: May 20, 1967).He is the Crown Prince of Greece, but the monarchy there was abolished in 1974.
Crown Prince Uikyung was born in 1438.
Crown prince Hyomyung was born in 1809.
Crown Prince Sado was born in 1735.
Crown Prince Sohyeon was born in 1612.
Crown Prince Eun was born on October 20, 1897.
Crown Prince Euimin was born on October 20, 1897.
Crown Prince Friedrich Ludwig was born in 1698.
Crown Prince Frederik of Denmark was born on May 26, 1968.
Crown Prince Wilhelm of Germany was born on May 6, 1882.
Crown Prince Rudolf of Austria was born on August 21, 1858.