# Divisors of the Positive Integer 81

1, 3, 9, 27, 81## Sum of all the Divisors of 81, including itself

121## Sum of the Proper Divisors of 81

40## Properties of the number 81

The integer 81 is an**odd**number.

The integer 81 is a

**Composite**number.

40 is

*less than*81, so 81 is a

**deficient**number.

## The number 81 as a Roman Numeral

**LXXXI**

## The number 81 in various Numeral Systems

Base |
Representation |
---|---|

2: | 1010001 |

3: | 10000 |

4: | 1101 |

5: | 311 |

6: | 213 |

7: | 144 |

8: | 121 |

9: | 100 |

10: | 81 |

11: | 74 |

12: | 69 |

13: | 63 |

14: | 5B |

15: | 56 |

16: | 51 |

17: | 4D |

18: | 49 |

19: | 45 |

20: | 41 |

21: | 3I |

22: | 3F |

23: | 3C |

24: | 39 |

25: | 36 |

26: | 33 |

27: | 30 |

28: | 2P |

29: | 2N |

30: | 2L |

31: | 2J |

32: | 2H |

33: | 2F |

34: | 2D |

35: | 2B |

36: | 29 |