900 (number)
natural number
900 (nine hundred) is the natural number following 899 and preceding 901.
In mathematics
It is the square of 30 and the sum of Euler's totient function for the first 54 positive integers. In base 10, it is a Harshad number. It is also the first number to be the square of a sphenic number.
In other fields
900 is also:
In Greek number symbols, the sign Sampi ("ϡ", literally "like a pi")
A skateboarding trick in which the skateboarder spins two and a half times (360 degrees times 2.5 is 900)
A 900 series refers to three consecutive perfect games in bowling
Yoda's age in Star Wars
Integers from 901 to 999
900s
901
901 = 17 × 53. It is a centered triangular number and a happy number.
902
902 = 2 × 11 × 41. It is a sphenic number, a nontotient, and a Harshad number.
903
903 = 3 × 7 × 43. It is a sphenic number, a little Schroeder number, a Schröder–Hipparchus number, a zero of Mertens function, and the 42nd triangular number.
Begin with the source’s own compact description: “900 (number)” is natural number. The dossier treats that line as a proposition to test through number and natural, not as a finished interpretation.
Why this record matters
The phrase “natural number” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The citation trail is more important than the brevity of the summary: it shows where individual claims can be examined in context. The source revision retrieved here is dated Aug 24, 2026. The linked authority identifier is Q741748. None of the 0 selected statements returned an explicit reference.
A concise general-reference account can conceal disagreements about scope, terminology or the weight assigned to individual sources. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “900 (number)”, its source revision and the description used here.
- Expand the search: follow 900 (number) primary sources, 900 (number) archive and number research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “900 (number)”?
- Which institution is responsible for the underlying evidence?
- Which cited source is closest to the event, object or claim?
Search terms from this dossier
This entry incorporates text from “900 (number)” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.