| ||||
---|---|---|---|---|
Cardinal | forty-seven | |||
Ordinal | 47th (forty-seventh) | |||
Factorization | prime | |||
Prime | 15th | |||
Divisors | 1, 47 | |||
Greek numeral | ΜΖ´ | |||
Roman numeral | XLVII | |||
Binary | 1011112 | |||
Ternary | 12023 | |||
Senary | 1156 | |||
Octal | 578 | |||
Duodecimal | 3B12 | |||
Hexadecimal | 2F16 |
47 (forty-seven) is the natural number following 46 and preceding 48. It is a prime number.
Forty-seven is the fifteenth prime number, a safe prime, [1] and the fourth isolated prime. [2] 47 is the number of trees on 9 unlabeled nodes. [3]
47 is the sixth highly cototient number, [4] and the eighth Eisenstein prime with no imaginary part and real part of the form . [5]
47 is the ninth strictly non-palindromic number, following 19 and preceding 53. [6]
47 is the largest member of the simplest Cunningham chain, [7]
where each prime member is one more than twice the previous. 47 is equivalently the fifth Thabit number of the form for positive , relating to the pair of amicable numbers {17296, 18416}.
47 is the ninth Lucas number (and sixth Lucas prime), [8] where it is also the fourth Keith number since its digits appear as successive terms earlier in the sequence of Lucas numbers: {2, 1, 3, 4, 7, 11, 18, 29, 47, ...}. [9]
47 is the thirteenth supersingular prime. [10] It is the last consecutive prime number that divides the order of at least one sporadic group, in its case it divides the order of the two largest such (non-pariah) groups: and . [11]
47 is the largest consecutive prime in Manjul Bhargava's prime-universality criterion theorem representative of all prime numbers: {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 67, 73}.
The forty-seventh triangular number (1128) is the dimensional representation of the largest vertex operator algebra with central charge of twenty-four, . [12]
47 is the atomic number of silver.
The 47-year cycle of Mars: after 47 years – 22 synodic periods of 780 days each – Mars returns to the same position among the stars and is in the same relationship to the Earth and Sun. The ancient Mesopotamians discovered this cycle. [13]
The number 47 has historical implications to Pomona College, a liberal arts college in Claremont, California, and has been incorporated into various aspects of campus life. [14] [15] The tradition began in the summer of 1964, when two students, Laurie Mets and Bruce Elgin, conducted a research project seeking to find out whether the number occurs more often in nature than would be expected by chance. They documented various 47 sightings, and professor Donald Bentley produced a false mathematical proof that 47 was equal to all other integers. The number became a meme among the class, which spread once the academic year began and snowballed over time. [16]
Notable 47 sightings include the fact that Pomona is located off of exit 47 of Interstate 10, and the fact that the largest residential building on campus, Mudd-Blaisdell (formally Florence Carrier Blaisdell and Della Mullock Mudd Hall, a title with 47 characters), was completed in 1947 and contains a staircase with 47 balusters. [16]
Many Pomona alumni have deliberately inserted 47 references into their work. [14] Joe Menosky (class of 1979), a writer for Star Trek: The Next Generation , inserted 47 mentions into nearly every episode of the show, a practice that has been picked up by other Star Trek writers. [16] [17] [18] Pomona hosts a community service–oriented celebration every April 7 (abbreviated 4/7 in the U.S.). [19] In the early 2010s, the college's clock tower was set up to chime on the 47th minute of the hour. [20] [21]Late rapper Capital Steez was infatuated with the number 47 and what it meant spiritually. He believed the number 47 was the "perfect expression of balance in the world", representing the tension between the heart and the brain (the fourth and sixth chakra, respectively.) The number featured on the cover of AmeriKKKan Korruption, stylized to resemble a swastika. [22]
23 (twenty-three) is the natural number following 22 and preceding 24.
35 (thirty-five) is the natural number following 34 and preceding 36.
71 (seventy-one) is the natural number following 70 and preceding 72.
73 (seventy-three) is the natural number following 72 and preceding 74. In English, it is the smallest natural number with twelve letters in its spelled out name.
31 (thirty-one) is the natural number following 30 and preceding 32. It is a prime number.
63 (sixty-three) is the natural number following 62 and preceding 64.
113 is the natural number following 112 and preceding 114.
1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000.
300 is the natural number following 299 and preceding 301.
500 is the natural number following 499 and preceding 501.
700 is the natural number following 699 and preceding 701.
600 is the natural number following 599 and preceding 601.
800 is the natural number following 799 and preceding 801.
2000 is a natural number following 1999 and preceding 2001.
3000 is the natural number following 2999 and preceding 3001. It is the smallest number requiring thirteen letters in English.
4000 is the natural number following 3999 and preceding 4001. It is a decagonal number.
5000 is the natural number following 4999 and preceding 5001. Five thousand is the largest isogrammic numeral in the English language.
6000 is the natural number following 5999 and preceding 6001.
7000 is the natural number following 6999 and preceding 7001.
In number theory, a branch of mathematics, a highly cototient number is a positive integer which is above 1 and has more solutions to the equation