The GCD of given numbers is 1.
| factors of 956 are : | 1 , 2 , 4 , 239 , 478 , 956 |
| factors of 988 are : | 1 , 2 , 4 , 13 , 19 , 26 , 38 , 52 , 76 , 247 , 494 , 988 |
| factors of 3063 are : | 1 , 3 , 1021 , 3063 |
| factors of 981 are : | 1 , 3 , 9 , 109 , 327 , 981 |
| factors of 1897 are : | 1 , 7 , 271 , 1897 |
| factors of 1013 are : | 1 , 1013 |
| factors of 1963 are : | 1 , 13 , 151 , 1963 |
| factors of 1966 are : | 1 , 2 , 983 , 1966 |
We see that the Greatest Common Factor = 1.