Английская Википедия:199 (number)

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Шаблон:Infobox number 199 (one hundred [and] ninety-nine) is the natural number following 198 and preceding 200.

In mathematics

199 is a centered triangular number.[1]

It is a prime number and the fourth part of a prime quadruplet: 191, 193, 197, 199.[2]

199 is the smallest natural number that takes more than two iterations to compute its digital root as a repeated digit sum: <math display=block> \begin{align} 199&\mapsto 1+9+9=19\\ &\mapsto 1+9=10\\ &\mapsto 1+0=1. \end{align}</math> Thus, its additive persistence is three, and it is the smallest number of persistence three.[3]

See also

References

Шаблон:Reflist

Шаблон:Commons category Шаблон:Integers