291 is the natural number following 290 and preceding 292.
In mathematics
- 291 is an odd composite number with two prime factor.[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.[4]
- 291 is the sum of 6 different 4th powers. It is the sum of 44+24+24+14+14+14.[5]
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.[6]
- On December 19, 2021, the greatest number of cakes eaten online simultaneously was achieved in Tanba, Japan. There were 291 cakes.[7]
- On October 25, 2014, the longest string instrument was created in Singapore. It was the ‘Earth Harp’ at a length of 291 m.[8]
- 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.[9]
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.[10]
References
- ^ "Facts about the integer". mathworld.wolfram.com.
- ^ "Semiprime". mathworld.wolfram.com.
- ^ Sloane, N. J. A. (ed.). "Sequence A014688". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A003146 (Positions of letter c in the tribonacci word abacabaabacababac... generated by a->ab, b->ac, c->a (cf. A092782))". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ Sloane, N. J. A. (ed.). "Sequence A003340 (Numbers that are the sum of 6 positive 4th powers)". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation.
- ^ "291 kg elephant bar deadlift". www/guinnessworldrecords.com.
- ^ "291 cakes eaten online". www.guinnessworldrecords.com.
- ^ "291 m long string instrument". www.guinnessworldrecords.com.
- ^ "2.91 m tall usable pogo stick". www.guinnessworldrecords.com.
- ^ "291 Alice". www.universguide.com. 27 March 2019.