Personalities of the Buddhist Suttas
[See just below. Well, I heard the description as above. mo. No offense to the good Vessavana!]
Kuvera aka: Vessavana
He is one of the Caatummahaaraajaano (The Four Kings of the Four Directions). King of Uttarakuru (the North). His royal residence is Aa.lakamandaa and his citadel Visaa.na. His messengers are Tatolaa, Tattolaa, Tatotalaa, Ojasi, Tejasi, Tatojasi, Suura, Raaja, Ari.t.tha and Nemi. His lotus-lake is called Dhara.nii. His sons are all called Inda. He rules over the northern clime and is lord of the Yakkhas, with a splendid retinue. He is a follower of the Buddha.
[The current Kuvera] was once a brahmin called Kuvera and owned a sugar-cane farm, where he worked seven mills. The produce of one mill he gave in charity, and when his profits increased he gave alms for twenty thousand years. After death he was born as one of the Caatummakaaraajika-devas. [the four gods of the four directions]
In literature the name Kuvera signifies the god of wealth, and his city, Aa.lakamandaa is said to embody all prosperity.
He is also known as Vessava.na from the name of his kingdom. He appears in the Aa.taanaatiya Sutta of the Digha Nikaya where he delivers the Aa.taanaatiya rune for the protection of bhikkhus. He is a sotaapanna and has a lifespan of 90,000 years..
As well as being a god of wealth he also 'appears to have been worshipped by those desiring children.'
Vessava.na is not the name of aparticular being but of the holder of an office. When one Vessava.na dies Sakka chooses another as his successor.
Information mostly extracted from DPPN
See also Hare's AN 7.50, where footnotes #5, 6, 7, and 8 deal with him and where referencing the commentaries it is stated he is a streamwinner, is symbolized by the Lion, is the God of Wealth, and was, at the time of Gotama 9,000,000 years old.
 See note above. According to AN 8.42 (see Hare: AN 8.42) The lifespan of the Caatummahaaraajaano, of which he is one, is calculated as follows: each fifty years of mankind is a single night and day; their month has thirty of those nights, their year twelve months the lifespan of those devas consists of five hundred celestial years, each equal to that year. That would be: 50X30X12X500 = 9,000,000 human years. And that is the calculation for the retinue of these gods, the Four Kings themselves are likely to have longer lifespans. If the note cited above is correct though, he appears to be near the end of his lifespan and could be reborn hear at any time give or take a few thousand years.