Number 47

A page of the Numeropedia - the Special Encyclopedia of Numbers

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[Chem.]  The atomic number of Silver (Ag).

[EECS]  47(W, KW or MW) is one of standard numerical values for resistors (of tolerance class 5%). 47pF (picofarads) and 47mF (microfarads) are two of standard numerical values for capacitors.

[History]  New Mexico became the 47th state of the U.S. on 6 January 1912.

[History]  The Winchester Mystery House in San Jose, Silicon Valley, California is an unfinished 160-room Victorian mansion with 47 fireplaces, which was built continuously in 38 years (1884 to 5 September 1922).

[Math.]  A 7-term arithmetic progression of prime numbers, of common difference 210: 47, 257, 467, 677, 887, 1097 and 1307.

[Math.]  The smallest case of 3 consecutive prime numbers in an arithmetic progression (of common difference 6): 47, 53 and 59.

[Math.]

94 = 47×2 and, reversely, 49 = 47+2

994 = 497×2 and, reversely, 499 = 497+2

9994 = 4997×2 and, reversely, 4999 = 4997+2

99994 = 49997×2 and, reversely, 49999 = 49997+2

...

999,999,999,994 = 499,999,999,997×2 and, reversely,

499,999,999,999 = 499,999,999,997+2

[Math.]

 33×34 = 1122 33×35 = 1155 33×36 = 1188 33×37 = 1221 33×47 = 1551 33×57 = 1881

 333×334 = 111,222 333×335 = 111,555 333×336 = 111,888 333×337 = 112,221 333×347 = 115,551 333×357 = 118,881

… (generalizable pattern) …

[Math.]  The 8th Lucas number.

[Math.]  The 4th Keith number: 4, 7, 11, 18, 29, 47, 76…

[Math.]  A supersingular prime numbers factors of the order of the Monster group M: 246×320×59×76×112×133×17×19×23×29×31×41×47×59×71 =

= 808017424794512875886459904961710757005754368000000000.

[Phone]  International telephone dialing code for Norway.

44 & 47

[History]  The 44th U.S. President: Barack Hussein Obama, Jr. (Democrat, Illinois, 2009-2013).

His Vice President, Joseph Robinette Biden, Jr. (Delaware), is the 47th U.S. Vice President.