261 (number): Difference between revisions
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'''261 may refer to:''' |
'''261 may refer to:''' |
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* [[261]] Fatima Koko, 261 locs |
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* [[261]] AD, a calendar year |
* [[261]] AD, a calendar year |
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* [[261 AM]], a radio frequency |
* [[261 AM]], a radio frequency |
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Revision as of 17:11, 11 May 2021
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| Cardinal | two hundred sixty-one | |||
| Ordinal | 261st (two hundred sixty-first) | |||
| Factorization | 32 × 29 | |||
| Divisors | 1, 3, 9, 29, 87, 261 | |||
| Greek numeral | ΣΞΑ´ | |||
| Roman numeral | CCLXI | |||
| Binary | 1000001012 | |||
| Ternary | 1002003 | |||
| Senary | 11136 | |||
| Octal | 4058 | |||
| Duodecimal | 19912 | |||
| Hexadecimal | 10516 | |||
261 (two hundred [and] sixty-one) is a natural number proceeded by the number 260 and followed by 262. It has the prime factorization 32·29.
Mathematical properties
There are six divisors of this number, the divisors being 1, 3, 9, 29, 87, and 261 itself.[1] 261 is a deficient number, since 1 + 3 + 9 + 29 + 87 = 129 < 261.
261 is nonagonal number, Harshad number, unique period in base 2, and the number of possible unfolded tesseract patterns.
261 is a lucky number, as well as an odious number, meaning it has an odd number of 1's in its binary expansion, which is 1000001012 (with 3 ones in it).[2]
261 was once the lowest number not to have its own Wikipedia page, this making it a candidate for the lowest uninteresting Number according to the definition given by Alex Bellos.[3] As of September 2018[update], the smallest natural number without its own Wikipedia page is 262, and the smallest prime number without its own Wikipedia page is 283.
In other fields
261 may refer to:
- 261 Fatima Koko, 261 locs
- 261 AD, a calendar year
- 261 AM, a radio frequency
- 261 BC, a calendar year
- 261 Fearless, a non-profit organization started by Kathrine Switzer, who in 1967 wore bib number 261 when she became the first woman to run the Boston Marathon as a numbered entrant
- +261, a country calling code; see telephone numbers in Madagascar
- H.261, an video compression standard
- Military / transportation
- Flight 261, several airliner incidents
- German submarine U-261, which was sunk in 1942
- KiHa 261 series, a type of diesel train in Japan
- Messerschmitt Me 261, an airplane of the late 1930s
- Milwaukee Road 261, a restored steam locomotive built in 1944
- No. 261 Squadron RAF, of World War I and World War II
- VMM-261, a United States Marine Corps squadron
- Space
- 261 Prymno, a minor planet
- Kosmos 261, a Soviet satellite launched in 1968
- NGC 261, a diffuse nebula located in the constellation Tucana
- See also
References
- ^ "Facts about the number 261". Numbermatics - the number explorer. Retrieved 2017-03-20.
- ^ "Number Gossip: 261". www.numbergossip.com. Retrieved 2017-03-20.
- ^ Bellos, Alex (June 2014). The Grapes of Math: How Life Reflects Numbers and Numbers Reflect Life. illus. The Surreal McCoy (1st Simon & Schuster hardcover ed.). N.Y.: Simon & Schuster. pp. 238 & 319 (quoting p. 319). ISBN 978-1-4516-4009-0.