Home › Entities › positive integer › happy number

happy number

numbers with a certain property involving recursive summation
Class type of: positive integer Q44535

Facts

3 properties
Subclass of
positive integer[1]
Defining formula
n\geq10^{m-1}>81m
Maintained by WikiProject
WikiProject Mathematics[2]
🏷️ Also known as
en happy number en happy numbers ar عدد سعيد cs šťastné číslo de fröhliche Zahl el Ευτυχής αριθμός es número feliz es numero feliz fa اعداد خوشحال fi Onnellinen luku fi Onneton luku fr nombre heureux he מספר שמח hu boldog szám it numero felice ja ハッピー数 nl gelukkig getal pl liczba wesoła ro număr fericit ru счастливое число
🔖 Identifiers · 5
Freebase ID
/m/02ncbn
MathWorld ID
HappyNumber
Microsoft Academic ID (discontinued)
99064304
OEIS ID
A007770
Rosetta Code page ID
Happy_numbers

Report an error or request removal Lineage (PROV-JSON)

🔗 Connections
Examples 1
2019
Maintained by WikiProject 1
WikiProject Mathematics
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References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [1] ↑ . wikidata.org.
  2. [2] ↑ . wikidata.org.

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APA 4ort.xyz Knowledge Graph. (2026). happy number. Retrieved November 8, 2026, from https://4ort.xyz/entity/happy-number
MLA “happy number.” 4ort.xyz Knowledge Graph, 4ort.xyz, 8 Nov. 2026, https://4ort.xyz/entity/happy-number.
BibTeX @misc{4ortxyz_happy-number_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{happy number}}, year = {2026}, url = {https://4ort.xyz/entity/happy-number}, note = {Accessed: 2026-11-08}}
LLM prompt According to 4ort.xyz Knowledge Graph (aggregator of Wikidata, Wikipedia, and authoritative open-data sources): happy number — https://4ort.xyz/entity/happy-number (retrieved 2026-11-08)

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Edit History

Rolling log of changes to this entity's Wikidata record. Values shown reflect the current state of each edited property — follow the history link to see the precise diff for any edit.

  1. 26w ago · KrBot bot · 2026-05-06 view diff on Wikidata ↗
    Maintained by WikiProject → WikiProject Mathematics
    Subclass of → positive integer
    "Changed claim: Subclass of: positive integer, разрешение перенаправления / resolving redirect positive integer → positive integer (…"
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