Next prime | 647 |

Previous prime | 641 |

Octal | (1203)_{8} |

Hexadecimal | (283)_{16} |

Prime gap | 4 |

29th Cousin prime (the small number) | The big number is 647 . |

56th Prime of the Form 3n+1 | 20^{2} + 3 * 9^{2} |

61st Prime of the Form 4n+3 | |

38th Left-truncatable prime |