257 (two hundred
ndfifty-seven) is the natural number following
256 and preceding
258
Year 258 ( CCLVIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Tuscus and Bassus (or, less frequently, year 1011 ''Ab urbe condi ...
.
In mathematics
257 is a
prime number
A prime number (or a prime) is a natural number greater than 1 that is not a Product (mathematics), product of two smaller natural numbers. A natural number greater than 1 that is not prime is called a composite number. For example, 5 is prime ...
of the form
specifically with ''n'' = 3, and therefore a
Fermat prime
In mathematics, a Fermat number, named after Pierre de Fermat, who first studied them, is a positive integer of the form
:F_ = 2^ + 1,
where ''n'' is a non-negative integer. The first few Fermat numbers are:
: 3, 5, 17, 257, 65537, 429496 ...
. Thus a
regular polygon with 257 sides is
constructible with compass and unmarked straightedge. It is currently the second largest known Fermat prime.
Analogously, 257 is the third
Sierpinski prime of the first kind, of the form
➜
.
It is also
a
balanced prime In number theory, a balanced prime is a prime number with equal-sized prime gaps above and below it, so that it is equal to the arithmetic mean of the nearest primes above and below. Or to put it algebraically, given a prime number p_n, where is it ...
,
an
irregular prime,
a prime that is one more than a square,
and a
Jacobsthal–Lucas number In mathematics, the Jacobsthal numbers are an integer sequence named after the German mathematician Ernst Jacobsthal. Like the related Fibonacci numbers, they are a specific type of Lucas sequence U_n(P,Q) for which ''P'' = 1, and '' ...
.
There are exactly 257 combinatorially distinct
convex polyhedra with eight
vertices (or
polyhedral graph
In geometric graph theory, a branch of mathematics, a polyhedral graph is the undirected graph formed from the vertices and edges of a convex polyhedron. Alternatively, in purely graph-theoretic terms, the polyhedral graphs are the 3-vertex-con ...
s with eight nodes).
In other fields
*The years
257
__NOTOC__
Year 257 ( CCLVII) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Valerianus and Gallienus (or, less frequently, year 10 ...
and
257 BC
*257 is the country calling code for
Burundi
Burundi (, ), officially the Republic of Burundi ( rn, Repuburika y’Uburundi ; Swahili: ''Jamuhuri ya Burundi''; French: ''République du Burundi'' ), is a landlocked country in the Great Rift Valley at the junction between the African Gr ...
. See
List of country calling codes
Country calling codes or country dial-in codes are telephone number prefixes for reaching telephone subscribers in the networks of the member countries or regions of the International Telecommunication Union (ITU). The codes are defined by the ...
.
*
.257 Roberts
The .257 Roberts, also known as .257 Bob, is a medium-powered .25 caliber rifle cartridge. It has been described as the best compromise between the low recoil and flat trajectory of smaller calibers such as the 5 mm (.22") and 6 mm (.24"), and ...
, rifle cartridge
*There is a Pac-Man themed restaurant called
Level 257 located in
Schaumburg, Illinois
Schaumburg ( ) is a village mostly in Cook County and partly in DuPage County in northeastern Illinois, United States. Per the 2020 Census, the population was 78,723. Schaumburg is around northwest of the Chicago Loop and northwest of O'Har ...
. It is in reference to the
kill screen
''Kill Screen'' (stylized as ''KILL SCREEN'') was a print and online magazine founded in 2009 by Jamin Warren and Chris Dahlen and owned by Kill Screen Media, Inc. It focused on video games and culture, but also included articles based on ...
reached in Level 256 in the
Pac-Man
originally called ''Puck Man'' in Japan, is a 1980 maze action video game developed and released by Namco for arcades. In North America, the game was released by Midway Manufacturing as part of its licensing agreement with Namco America. Th ...
arcade game.
*
257ers
The Media Control charts are record charts compiled by Media Control on behalf of the German record industry. They include the "Single Top 100" and the "Album Top 100" chart. The chart week runs from Friday to Thursday, and the chart compilation ...
is a German hip hop duo
References
{{DEFAULTSORT:257 (Number)
Integers