What is a Capicúa Number? Beliefs and curiosities

He Capicua number Is a figure that reads in the same way from left to right, than from right to left. The reading of the number must always be the same. The word capicúa comes from the expression in Catalan"cap i cua", which means"head and tail".

Likewise, capicuous numbers are also known as palindromes. This denomination comes from the Greek"palin drome", which means"that goes in reverse", although its use is more inclined to be used in words or phrases.

Capicuous numbers and popular beliefs

For the superstitious, the dates in capicúas numbers possess fatalistic qualities and characteristics, or on the contrary, of good luck and fortune.

• On February 20, 2002 (02-02-2002) was reported in the world press, as the phenomenon of a capicúa date was presented after almost 1000 years, being the last time on November 11, 1111 (11-11-1111).
• In ancient Greece they attributed mystical properties to capicuous numbers, coming to think that on such dates there would be great natural catastrophes and until the end of the world.
• When a capicúa number appears in tickets, tickets, digital clocks, carnets, serials of any kind and other objects, it is considered good luck by some cultures, due to the rarity of its nature.
• In Buenos Aires, Argentina, tickets were produced for the tram that took the numbering from 00000 to 99999, for a total of 100,000 tickets. Which generated 1000 numbers capicúas per each series. The majority of the users had the belief that the rarity of those tickets, would give the holder some type of prize throughout the day. Even today they are considered of great value by collectors.
• The"666"is known as the number of the antichrist, in the biblical book called Apocalypse, and is usually associated with evil and the demonic.

Capicuous numbers and their curiosities

• All primary numbers are capicua, because they meet the definition of reading the same in both directions.
• In the figures of 2 digits ranging from 10 to 99, we find a total of 9 numbers capicúa, for example: 11, 22, 33,..., 88 and 99.
• In the 3-digit numbers ranging from 100 to 999, we find a total of 93 capicuous numbers, for example: 101, 111, 121,131,... 191, 202, 212, 222,..., 333, 343, 353, 363 , 454, 464, 474, 484,..., 979, 989, 999.
• In the figures of 4 digits ranging from 1000 to 9999 we find a total of 94 capicuous numbers, for example: 1001, 1111, 1221, 1331,..., 2332,..., 8118,..., 9889, 9999.
• In the figures of 5 digits that go from the 10000 to the 99999 we find a total of 905 numbers capicúas, for example: 10001,..., 27872,..., 53135,..., 79397,..., 99999.
• Many of the digits of two digits or more, combined with the numbers in reverse, will result in a capicua number, for example: 71 + 17 = 88, 514 + 415 = 929, 841 + 148 = 989
• In the domino, popular board game in Latin America, the name capicua is used in an unusual way. On the Island of Puerto Rico, for example, when a player closes a play by placing a piece with the same number that is on the opposite end, he usually shouts:"capicúa!".

References

1. Caballero Rubio, S., & García García, F. (1995). Material Use Guide. Compulsory Secondary Education. . Ministry of Education and Science.
2. Capicúa. (S.f.). Wikipedia. The Free Encyclopedia . Recovered on 30 of 08 of 2017, of es.wikipedia.org.
3. Hargittai, I. (2016). Symmetry 2: Unifying Human Understanding. Pergamon Press.
4. Hernández Guerrero, J.A. (2006). The Words of Fashion. Cadiz: EDITUM.
5. Number of Content (S.f.). Recovered on 30 of 08 of 2017, of Numerode.com.
6. Palindromic Number. (17 of 08 of 2017). Wikipedia, The Free Encyclopedia. Recovered on 30 of 08 of 2017, of en.wikipedia.org.
7. Pickover, C.A. (2003). Wonders of Numbers: Adventures in Mathematics, Mind, and Meaning. New York: Oxford University Press.