291 (number) explained

Number:	291
Divisor:	1, 3, 97, 291

291 is the natural number following 290 and preceding 292.

In mathematics

• 291 is an odd composite number with two prime factors.^[1]
• 291 is a semiprime number meaning that it has 2 prime factors.^[2]
• 291 can be written as the sum of the nth prime plus n. It is the 52nd prime (239) plus 52.^[3]
• 291 is one of the positions of “c” in the tribonacci word abacabaab… defined by a->ab, b->ac, c->a.
• 291 is the sum of 6 different 4th powers. It is the sum of 44+24+24+14+14+14.

World Records

• On March 6, 2022, Tamara Walcott received the Guinness World Record for the elephant bar deadlift achieved by a woman. She lifted a weight of 291 kg.^[4]
• On December 19, 2021, the greatest number of cakes eaten online simultaneously was achieved in Tanba, Japan. There were 291 cakes.^[5]
• On October 25, 2014, the longest string instrument was created in Singapore. It was the ‘Earth Harp’ at a length of 291 m.^[6]
• On August 7, 2011, Fred Grsybowski achieved the Guinness World Record for the tallest usable pogo stick in Toronto. It was 2.91 m tall.^[7]

Other fields

• The calendar years 291 AD and 291 BC.
• 291 is the number for several highways across the countries of Canada, Japan, and the United States.
• 291 Alice is an asteroid in the asteroid belt. It was discovered by Johann Palisa in Vienna, Austria.^[8]

Notes and References

1. Web site: Facts about the integer. mathworld.wolfram.com.
2. Web site: Semiprime. mathworld.wolfram.com.
3. n-th prime + n.
4. Web site: 291 kg elephant bar deadlift. www/guinnessworldrecords.com.
5. Web site: 291 cakes eaten online. www.guinnessworldrecords.com.
6. Web site: 291 m long string instrument. www.guinnessworldrecords.com.
7. Web site: 2.91 m tall usable pogo stick. www.guinnessworldrecords.com.
8. Web site: 291 Alice. www.universguide.com. 27 March 2019 .