145 (number)
title: "145 (number)" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["integers"] topic_path: "general/integers" source: "https://en.wikipedia.org/wiki/145_(number)" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::data[format=table title="Infobox number"]
| Field | Value |
|---|---|
| number | 145 |
| divisor | 1, 5, 29, 145 |
| :: |
| number = 145 | divisor=1, 5, 29, 145
145 (one hundred [and] forty-five) is the natural number following 144 and preceding 146.
In mathematics
- Although composite, 145 is a Fermat pseudoprime in sixteen bases with b
- The Mertens function returns 0.
- 145 is a pentagonal number and a centered square number.
- 145 = 12^2 + 1^2 = 8^2 + 9^2. 145 is the fourth number that is the sum of two different pairs of squares. Also, 145 is the result of 34 + 43, making it a Leyland number.
- 145 = 1! + 4! + 5!, making it a factorion. The only other numbers that have this property are 1, 2 and 40585.
- 145=5^2+5!=11^2+4!=12^2+1!, making 145 the smallest number that can be written as the sum of a square number and a factorial in 3 ways. The next number with this property is 46249.
References
- Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 140
References
- "Sloane's A028442 : Numbers n such that Mertens' function is zero". OEIS Foundation.
- "Sloane's A000326 : Pentagonal numbers". OEIS Foundation.
- "Sloane's A001844 : Centered square numbers". OEIS Foundation.
- "Sloane's A014080 : Factorions". OEIS Foundation.
- "A359013 - OEIS". OEIS Foundation.
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