The fifth Sophie Germain prime and the fourth safe prime, 23 is the next to last member of the first Cunningham chain of the first kind to have five terms (2, 5, 11, 23, 47). Since 14! + 1 is a multiple of 23 but 23 is not one more than a multiple 14, 23 is a Pillai prime. 23 is the smallest odd prime to be a highly cototient number, as the solution to x − φ(x) for the integers 95, 119, 143, 529.
Twenty-three is the aliquot sum of two integers; the discrete semiprimes 57 and 85 and is the base of the 23-aliquot tree.
23 is the first prime P for which unique factorization of cyclotomic integers based on the Pth root of unity breaks down.
The sum of the first 23 primes is 874, which is divisible by 23, a property shared by few other numbers.
In the list of fortunate numbers, 23 occurs twice, since adding 23 to either the fifth or eighth primorial gives a prime number (namely 2333 and 9699713).
23 also has the distinction of being one of two integers that cannot be expressed as the sum of fewer than 9 cubes of integers (the other is 239). See Waring's problem.
23 is a Wedderburn–Etherington number. The codewords in the perfect (non-extended) binary Golay code are of size 23.
According to the birthday paradox, in a group of 23 (or more) randomly chosen people, the probability is more than 50% that some pair of them will have the same birthday.
There were 23 problems on David Hilbert's famous list of unsolved mathematical problems, presented to the International Congress of Mathematicians in Paris in 1900.
In base 10, 23 is the second Smarandache–Wellin prime, as it is the concatenation of the base 10 representations of the first two primes (2 and 3) and is itself also prime. It is also a happy number in base 10. 23! is 23 digits long in base 10. There are only three other numbers that have this property: 1, 22, and 24.
The natural logarithms of all positive integers lower than 23 are known to have binary BBP-type formulae.
The number 23 has been worn by and sometimes retired for a number of few prominent athletes. Michael Jordan wore number 23 when he played professional basketball with the Chicago Bulls and, later, the Washington Wizards -- except immediately following his comeback from baseball, when he wore number 45, and for one game in the 1990-91 season against the Orlando Magic when his jersey was stolen and he wore the number 12. Australian cricketer Shane Warne wore the number 23 during his career; Don Mattingly of the New York Yankees wore number 23; the New York Yankees retired the number in 1997. Ryne Sandberg, of the Chicago Cubs, wore number 23, which was retired on August 28, 2005. Bob Nystrom of the New York Islanders wore number 23 and has had the number retired in his honour. Bob Gainey, ex-General Manager and former player for the Montreal Canadiens, had his number 23 retired February 23, 2008.
Manchester City F.C. retired their number 23 shirt in 2003 following the death of Marc-Vivien Foé who had held this squad number at the club. Foé collapsed and died while playing for Cameroon on June 26, 2003. Belgian team Brugge did the same when their number 23, François Sterchele, died in a car accident on May 8, 2008.
Upon signing for Real Madrid from Manchester United in 2003 David Beckham found the number 7 shirt that he had always worn at Manchester and while on England duty occupied by Madrid hero Raúl. He declined the offer of the number 4 shirt recently vacated by departing captain Fernando Hierro and instead picked the number 23 in deference to Michael Jordan. When he then moved to MLS team Los Angeles Galaxy in 2007, he again chose to wear the number 23 jersey. Later, when he was on loan at AC Milan during the American off-season, he wore the reversed number 32 instead as the number 23 was already in use at the club.
In Darts, 23 is "the lowest score you cannot get with a single Dart".
This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
The World News (WN) Network, has created this privacy statement in order to demonstrate our firm commitment to user privacy. The following discloses our information gathering and dissemination practices for wn.com, as well as e-mail newsletters.
We do not collect personally identifiable information about you, except when you provide it to us. For example, if you submit an inquiry to us or sign up for our newsletter, you may be asked to provide certain information such as your contact details (name, e-mail address, mailing address, etc.).
When you submit your personally identifiable information through wn.com, you are giving your consent to the collection, use and disclosure of your personal information as set forth in this Privacy Policy. If you would prefer that we not collect any personally identifiable information from you, please do not provide us with any such information. We will not sell or rent your personally identifiable information to third parties without your consent, except as otherwise disclosed in this Privacy Policy.
Except as otherwise disclosed in this Privacy Policy, we will use the information you provide us only for the purpose of responding to your inquiry or in connection with the service for which you provided such information. We may forward your contact information and inquiry to our affiliates and other divisions of our company that we feel can best address your inquiry or provide you with the requested service. We may also use the information you provide in aggregate form for internal business purposes, such as generating statistics and developing marketing plans. We may share or transfer such non-personally identifiable information with or to our affiliates, licensees, agents and partners.
We may retain other companies and individuals to perform functions on our behalf. Such third parties may be provided with access to personally identifiable information needed to perform their functions, but may not use such information for any other purpose.
In addition, we may disclose any information, including personally identifiable information, we deem necessary, in our sole discretion, to comply with any applicable law, regulation, legal proceeding or governmental request.
We do not want you to receive unwanted e-mail from us. We try to make it easy to opt-out of any service you have asked to receive. If you sign-up to our e-mail newsletters we do not sell, exchange or give your e-mail address to a third party.
E-mail addresses are collected via the wn.com web site. Users have to physically opt-in to receive the wn.com newsletter and a verification e-mail is sent. wn.com is clearly and conspicuously named at the point of
collection.If you no longer wish to receive our newsletter and promotional communications, you may opt-out of receiving them by following the instructions included in each newsletter or communication or by e-mailing us at michaelw(at)wn.com
The security of your personal information is important to us. We follow generally accepted industry standards to protect the personal information submitted to us, both during registration and once we receive it. No method of transmission over the Internet, or method of electronic storage, is 100 percent secure, however. Therefore, though we strive to use commercially acceptable means to protect your personal information, we cannot guarantee its absolute security.
If we decide to change our e-mail practices, we will post those changes to this privacy statement, the homepage, and other places we think appropriate so that you are aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it.
If we make material changes to our e-mail practices, we will notify you here, by e-mail, and by means of a notice on our home page.
The advertising banners and other forms of advertising appearing on this Web site are sometimes delivered to you, on our behalf, by a third party. In the course of serving advertisements to this site, the third party may place or recognize a unique cookie on your browser. For more information on cookies, you can visit www.cookiecentral.com.
As we continue to develop our business, we might sell certain aspects of our entities or assets. In such transactions, user information, including personally identifiable information, generally is one of the transferred business assets, and by submitting your personal information on Wn.com you agree that your data may be transferred to such parties in these circumstances.