As of 2022-03-07, the Wikidata property XXI Secolo ID (P9935) is used on 69 items as main value on statements (not counting qualifiers) of the Q and P namespaces.

Closest properties: by cardinality of intersection, by Jaccard index.

Display properties of the following types:                                    

Closest properties by cardinality of intersection

IDLabelIntersection cardinalityJaccard index
P279 subclass of 59
 0.0000
P646 Freebase ID 51
 0.0000
P910 topic's main category 50
 0.0001
P373 Commons category 47
 0.0000
P3417 Quora topic ID 44
 0.0002
P244 Library of Congress authority ID 42
 0.0000
P227 GND ID 40
 0.0000
P10283 OpenAlex ID 38
 0.0004
P2347 YSO ID 37
 0.0016
P3827 JSTOR topic ID 37
 0.0015
P31 instance of 36
 0.0000
P6366 Microsoft Academic ID 35
 0.0001
P508 BNCF Thesaurus ID 34
 0.0021
P8189 National Library of Israel J9U ID 34
 0.0002
P268 Bibliothèque nationale de France ID 32
 0.0001
P1417 Encyclopædia Britannica Online ID 31
 0.0002
P8408 KBpedia ID 28
 0.0007
P486 MeSH descriptor ID 25
 0.0007
P18 image 25
 0.0000
P3219 Encyclopædia Universalis ID 24
 0.0007
P2581 BabelNet ID 22
 0.0003
P1889 different from 22
 0.0000
P1051 PSH ID 21
 0.0035
P1014 Art & Architecture Thesaurus ID 21
 0.0009
P1245 OmegaWiki Defined Meaning 20
 0.0017
P672 MeSH tree code 20
 0.0012
P3095 practiced by 19
 0.0047
P349 National Diet Library ID 19
 0.0001
P2924 Great Russian Encyclopedia Online ID 18
 0.0004
P2004 NALT ID 17
 0.0026
P3553 Zhihu topic ID 17
 0.0012
P3916 UNESCO Thesaurus ID 16
 0.0052
P1343 described by source 16
 0.0000
P7818 French Vikidia ID 15
 0.0007
P3365 Treccani ID 15
 0.0006
P4527 UK Parliament thesaurus ID 15
 0.0006
P7033 Australian Educational Vocabulary ID 14
 0.0016
P361 part of 14
 0.0000
P2671 Google Knowledge Graph ID 14
 0.0000
P4212 PACTOLS thesaurus ID 13
 0.0008
P4342 Store norske leksikon ID 13
 0.0002
P5437 EuroVoc ID 12
 0.0039
P1296 Gran Enciclopèdia Catalana ID 12
 0.0001
P5008 on focus list of Wikimedia project 12
 0.0000
P3984 subreddit 11
 0.0010
P950 Biblioteca Nacional de España ID 11
 0.0001
P1225 U.S. National Archives Identifier 11
 0.0000
P9100 GitHub topic 10
 0.0040
P3569 Cultureel Woordenboek ID 10
 0.0019
P8529 ANZSRC 2020 FoR ID 9
 0.0083

Closest properties by Jaccard index

IDLabelIntersection cardinalityJaccard index
P9868 INAPP Thesaurus ID 2
 0.0161
P2612 TED topic ID 6
 0.0142
P10438 Norwegian thesaurus on genre and form identifier 1
 0.0139
P3612 Le Monde diplomatique subject ID 8
 0.0110
P5922 ANZSRC 2008 FoR ID 7
 0.0109
P10329 ICPSR Subject Thesaurus ID 1
 0.0105
P8374 Criminological Thesaurus ID 1
 0.0102
P5445 Language Council of Norways termwiki ID 1
 0.0099
P9982 IGI Global Dictionary ID 1
 0.0099
P3270 compulsory education (minimum age) 1
 0.0086
P9346 France24 topic ID (French) 2
 0.0085
P8529 ANZSRC 2020 FoR ID 9
 0.0083
P10037 Enciclopedia della Scienza e della Tecnica ID 1
 0.0082
P8717 ILO Thesaurus ID 2
 0.0079
P6492 BVPH authority ID 1
 0.0078
P2981 UIC alphabetical country code 1
 0.0076
P2982 UIC numerical country code 1
 0.0075
P9084 ABC News topic ID 8
 0.0072
P5429 IPTC NewsCode 6
 0.0072
P7996 EH.Net Encyclopedia of Economic and Business History ID 1
 0.0070
P10203 All-Science Journal Classification Codes 2
 0.0069
P9775 Treccani's Lessico del XXI Secolo ID 2
 0.0066
P10059 Philosophica ID 1
 0.0065
P3238 trunk prefix 1
 0.0062
P9983 Enciclopedia dei ragazzi ID 1
 0.0061
P6541 Stack Exchange site 1
 0.0060
P3271 compulsory education (maximum age) 1
 0.0060
P5748 Basisklassifikation 3
 0.0058
P9286 Encyclopaedia Herder concept ID 1
 0.0055
P4644 ESCO skill ID 2
 0.0052
P3916 UNESCO Thesaurus ID 16
 0.0052
P3067 GS1 country code 1
 0.0051
P9526 Scholarpedia article ID 1
 0.0051
P3235 PhilPapers topic 4
 0.0050
P8539 ERIC Thesaurus ID 1
 0.0049
P8476 BTI Governance Index 1
 0.0049
P8477 BTI Status Index 1
 0.0049
P8370 UNBIS Thesaurus ID 2
 0.0048
P3095 practiced by 19
 0.0047
P9368 CNA topic ID 2
 0.0045
P8483 PM20 geo code 1
 0.0045
P7712 Joconde domain ID 1
 0.0045
P6680 MeSH term ID 1
 0.0045
P2855 VAT-rate 1
 0.0043
P7387 Q-Codes ID 1
 0.0043
P8328 Democracy Index 1
 0.0043
P1304 central bank 1
 0.0042
P9100 GitHub topic 10
 0.0040
P2573 number of out-of-school children 1
 0.0040
P5437 EuroVoc ID 12
 0.0039