195 (one hundred
ndninety-five) is the
natural number
In mathematics, the natural numbers are those numbers used for counting (as in "there are ''six'' coins on the table") and ordering (as in "this is the ''third'' largest city in the country").
Numbers used for counting are called ''Cardinal n ...
following
194 and preceding
196
Year 196 ( CXCVI) was a leap 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 Dexter and Messalla (or, less frequently, year 949 ''Ab urbe condita ...
.
In mathematics
195 is:
* the sum of eleven consecutive primes:
3 +
5 +
7 +
11 +
13 +
17 +
19 +
23 +
29 +
31 +
37
* the smallest number expressed as a sum of distinct
square
In Euclidean geometry, a square is a regular quadrilateral, which means that it has four equal sides and four equal angles (90- degree angles, π/2 radian angles, or right angles). It can also be defined as a rectangle with two equal-length a ...
s in 16 different ways
* a
centered tetrahedral number
* in the middle of a
prime quadruplet
In number theory, a prime quadruplet (sometimes called prime quadruple) is a set of four prime numbers of the form This represents the closest possible grouping of four primes larger than 3, and is the only prime constellation of length 4.
Prim ...
(191, 193, 197, 199).
See also
*
195 (disambiguation)
References
{{DEFAULTSORT:195 (Number)
Integers