199 (one hundred
ndninety-nine) 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 ...
following 198 and preceding
200
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Year 200 ( CC) was a leap year starting on Tuesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Severus and Victorinus (or, less frequently, year 953 ''Ab ur ...
.
In mathematics
199 is a
centered triangular number
A centered (or centred) triangular number is a centered figurate number that represents an equilateral triangle with a dot in the center and all its other dots surrounding the center in successive equilateral triangular layers.
The followin ...
.
It 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 ...
and the fourth part of a
prime quadruplet:
191,
193
Year 193 ( CXCIII) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Sosius and Ericius (or, less frequently, year 946 ''Ab urbe condit ...
,
197, 199.
It is an
emirp, given that the reversal of its digits is also prime (991).
199 is the smallest natural number that takes more than two iterations to compute its
digital root as a repeated digit sum:
Thus, its
additive persistence is three, and it is the smallest number of persistence three.
See also
* The year
AD 199
Year 199 ( CXCIX) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was sometimes known as year 952 ''Ab urbe condita''. The denomination 199 for this year has been used since the ...
or
199 BC
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Year 199 BC was a year of the pre-Julian Roman calendar. At the time it was known as the Year of the Consulship of Lentulus and Tappulus (or, less frequently, year 555 ''Ab urbe condita''). The denomination 199 BC for this year has bee ...
*
List of highways numbered 199
*
References
{{Integers, 1
Integers