1, 3, 9.
8 of them.
They are 1, 3, 9, 27.
1, 3, 9, 27, 81.
The positive integer factors of 261 are: 1, 3, 9, 29, 87, 261
The positive integer factors of 1251 are: 1, 3, 9, 139, 417, 1251
The positive integer factors of 531 are: 1, 3, 9, 59, 177, 531
The positive integer factors of 387 are: 1, 3, 9, 43, 129, 387
The positive integer factors of 981 are: 1, 3, 9, 109, 327, 981
The positive integer factors of 81 are:1, 3, 9, 27, 81
The positive integer factors of 3771 are: 1, 3, 9, 419, 1257, 3771
The positive integer factors of 1017 are: 1, 3, 9, 113, 339, 1017
Well, honey, the positive odd factors of 36 are 1, 3, and 9. Add those bad boys up and you get 13. So, the sum of the positive odd factors of 36 is 13. Hope that satisfies your math cravings, sweetie!