180 (number)

From Wikipedia, the free encyclopedia

180 (one hundred eighty in American English, one hundred and eighty in British English) is the natural number following 179 and preceding 181.

List of numbers — Integers

<< 180 181 182 183 184 185 186 187 188 189 >>

Ordinal

One hundred [and]
eighty

Cardinal

180th

Factorization

$2^2 \cdot 3^2 \cdot 5$

CLXXX

10110100

130

[edit] In mathematics

One hundred [and] eighty is the sum of six consecutive primes (19 + 23 + 29 + 31 + 37 + 41), as well as the sum of eight consecutive primes (11 + 13 + 17 + 19 + 23 + 29 + 31 + 37).

The sum of Euler's totient function φ(x) over the first twenty-four integers is 180. Since 180 is divisible by the total number of its divisors, it is a refactorable number.

Using degrees (°) to measure angles, 180° is called straight angle, and makes a semicircle. 180° is equivalent to π rads. In normal space, the interior angles of a triangle add up to 180°.

180 is a Harshad number in base 10.

[edit] In other fields

180° also means antipode. For example, a "180-degree change" indicates a radical change.
Interstate 180, the designation of some spur routes of Interstate 80 in the United States.
The maximum possible score in one turn at darts (three treble 20s).
In astronomy, when two planets are 180 degrees apart, they are said to be in opposition. In astrology, this is an aspect that is considered to be negative in influence.
The year AD 180 or 180 BC.
180 is a perfect score on the LSAT. Thus, it is often used by law students and attorneys in conversation to signify agreement or appreciation of a point.
In the movie series Final Destination, Final Destination 2, and Final Destination 3, 180 is a number that often foreshadows death and suffering (FD1: Plane that blew up was Flight 180; FD2: Sign showing "Next 180 feet" during pile-up; FD3: Subway car was car 081, which is 180 backward)