A page of the Numeropedia - the Special Encyclopedia of Numbers
[EECS] 390(W, KW or MW) is one of standard numerical values for resistors (of tolerance class 5%). 390pF (picofarads) is one of standard numerical values for capacitors.
[Sport] The number of dimples on a golf ball usually are: 252, 286, 332, 336, 360, 384, 392, 410, 416, 420, 422, 432, 440, 480, 492 or 500. (References )
[World] The ISO country code for Japan. (ISO-3166)
[Library] ISBN-0-393 is the International Standard Book Number for books published by W. W. Norton & Company.
[Library] ISBN-0-394 is the International Standard Book Number for books published by Vintage Books or Alfred A. Knopf (of Random House).
[Math.] The numbers 199989394, 199989404 and 199989464 begin with the digits 394, 404 and 464 respectively.
[Library] ISBN-0-395 is the International Standard Book Number for books published by Houghton Mifflin Company.
[Tech.] The unmanned Global Hawk spy plane, entered the service in 2003, has maximum altitude of 65,000 feet, cruising peed of 395 mph, flight range of 16,111 miles and wing span of 130.9 feet. It begins the first surveillance missions over the USA on 20 November 2006.
[Math.] A prime number.
[World] The ISO country code for Kazakhstan. (ISO-3166)
[Tech.] The height (feet) of the USA tallest airport-control tower at Atlanta’s Hartsfield-Jackson airport.
[Library] ISBN-0-399 is the International Standard Book Number for books published by G. P. Putnam/Penguin Group.
[Library] Numbers 300-399 are the first 3 digits in Dewey Decimal Classification System call numbers for library books in Social Sciences (Economics, Government and Education…). Numbers 390-399 are for books in Customs, Etiquette and Folklore…
References : Scientific American, I. Stewart, Mathematical Recreations, February 1997.