Aragorn's people are Dúnedain [Men of the West, Númenórean in Quenya] which means they have different sinews than other men. They're stronger, taller, longer-lived, and hold onto their vitality late in life. Aragorn is directly descended from the male line through Isildur and from the female line from Anarion through Fíriel [who married Arvedui, last King of Arthedain], daughter of King Ondoher. Generally the line of Elros were the longer lived of the Dúnedain and during the final third of the 3rd Age Aragorn's descendants generally lived between 155-160 years of age. They held the title of Chieftains, but before their lands were overrun by Angmar his line ruled Arthedain and before that all of Arnor.
There was a time during the Rebellion on their homeland of Númenor that the King's Men who were made up of the majority of the Númenóreans rebelled against the Valar. The ruling Kings and Queens had a drastic drop in their lifespans and their other gifts so that there was no distinction between them and any other Dúnedain. This distinction is mentioned in Aldarion and Erendis as such:
this rule of "royal marriage" was never a matter of law, but it became
a custom of pride: "a symptom of the growth of the Shadow, since it
only became rigid when the distinction between the Line of Elros and
other families, in life-span, vigour, or ability, had diminished or
However, other members of the Line of Elros, such as the Lords of Andúnië, did not have such a drastic drop in their lifespans even though the shadow touched their hearts as well. For example, Elendil, Isildur's father died when he was 322 at the hands of Sauron during the Siege of Mordor. The Last King of Númenor, who was his cousin, "felt the shadow of death approach" when he was "besotted, and walking under the shadow of death" [Akallabêth] when has was barely 200 years old. Ar-Pharazôn's father had died when he was 198.
In Middle-earth the diminishment of the Dúnedain continued. It
was not a normal tendency, shared by the peoples whose proper home was
Middle-earth, but due to the loss of their ancient land far in he
West, nearest of all mortal lands to the Undying Realm. [Disaster of
the Gladden Fields; Númenórean Linear Measures]
Most of the Dúnedain had a life expectancy of around 100 or so. For the royal line in the North it was 155-160. Aragorn lived for 210 years.