cut -f1 <iprscan output file> | sort -u | wc -l

simply count the number of predicted gene IDs in the interpro output file

You could give a try to this script gff3_sp_functional_statistics.pl from the GAAS repository. You will end up with something like that. This one is a bit verbose (Functions come from interproscan analysis) compare to what you can get in your case.

 ________________________________________________________________________________________
|          |  Nb term linked to mRNA |    Nb mRNA with term    |    Nb gene with term    |
|________________________________________________________________________________________|
|  PANTHER |            67           |            36           |            28           |
|________________________________________________________________________________________|
|   Pfam   |            37           |            36           |            29           |
|________________________________________________________________________________________|
|   PRINTS |            1            |            1            |            1            |
|________________________________________________________________________________________|
| SUPERFAMI|            21           |            19           |            14           |
|________________________________________________________________________________________|
|   Coils  |            16           |            16           |            12           |
|________________________________________________________________________________________|
|   Gene3D |            17           |            16           |            12           |
|________________________________________________________________________________________|
|    CDD   |            7            |            7            |            4            |
|________________________________________________________________________________________|
| ProSitePa|            3            |            3            |            3            |
|________________________________________________________________________________________|
|   SMART  |            12           |            10           |            6            |
|________________________________________________________________________________________|
| InterPro |            84           |            39           |            32           |
|________________________________________________________________________________________|
| MobiDBLit|            39           |            39           |            29           |
|________________________________________________________________________________________|
| Ontology_|            58           |            27           |            21           |
|________________________________________________________________________________________|
|  TIGRFAM |            1            |            1            |            1            |
|________________________________________________________________________________________|
| ProSitePr|            20           |            14           |            10           |
|________________________________________________________________________________________|
| Reactome |            54           |            2            |            2            |
|________________________________________________________________________________________|

nb mRNA without Functional annotation (CDD,Coils,Gene3D,InterPro,MobiDBLite,Ontology_term,PANTHER,PRINTS,Pfam,ProSitePatterns,ProSiteProfiles,Reactome,SMART,SUPERFAMILY,TIGRFAM)=  0
nb mRNA with Functional annotation (CDD,Coils,Gene3D,InterPro,MobiDBLite,Ontology_term,PANTHER,PRINTS,Pfam,ProSitePatterns,ProSiteProfiles,Reactome,SMART,SUPERFAMILY,TIGRFAM) = 110  
nb gene without Functional annotation (CDD,Coils,Gene3D,InterPro,MobiDBLite,Ontology_term,PANTHER,PRINTS,Pfam,ProSitePatterns,ProSiteProfiles,Reactome,SMART,SUPERFAMILY,TIGRFAM) = 0  
nb gene with Functional annotation (CDD,Coils,Gene3D,InterPro,MobiDBLite,Ontology_term,PANTHER,PRINTS,Pfam,ProSitePatterns,ProSiteProfiles,Reactome,SMART,SUPERFAMILY,TIGRFAM) = 72  

We found 17 gene with <Name> attribute. 
We found 28 mRNA with <Name> attribute. They probably have the same names as their parent genes. 
We have 110 mRNA with <product> attribute.