+991 is a [natural number](/wiki/Natural_number) that follows 990 and precedes 992. It is notable as a [prime number](/wiki/Prime_number), divisible only by itself and one, and also recognized as a significant model designation.
+## See also
+- [Number](/wiki/Number)
+- [Prime](/wiki/Prime)
+- [Porsche 911](/wiki/Porsche_911)
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