🔼The name Dathan in the Bible
There's only one Dathan in the Bible. He and his brother Abiram, sons of Eliab of Reuben, and 250 elders of Israel joined Korah the son of Izhar of Levi in a rebellion against Moses and Aaron (Numbers 16:1).
When Moses wanted to talk with them, Korah listened to his explanations but Dathan and Abiram wouldn't even show up (16:12). Their fate was dire.
The two brothers and their families whom they obviously had contaminated with their insolent ideas, descended live into Sheol along with Korah (16:27, also see 26:11). The 250 others were incinerated (16:35) and their fire pans were hammered into plating for the altar as a continuing reminder to everybody that only the descendants of Aaron could approach the tabernacle and burn incense to YHWH (16:40).
The sin of Dathan and Abiram was obviously so utterly grim that their story was told again in Numbers 26:9, again in Deuteronomy 11:6 and once more in Psalm 106:17.
🔼Etymology of the name Dathan
The letter ן (nun) upon which our name ends may be the pronominal suffix meaning "his" or "their"; it may be an intensifier and it may be a quantifier.
For a meaning of the name Dathan, both NOBSE Study Bible Name List and Alfred Jones (Dictionary of Old Testament Proper Names) go with the Chaldean word דת meaning well or fountain. NOBSE simply reads Fount but Jones sees in the final nun the pronominal suffix and reads Belonging To A Fountain or Their Fountain. BDB Theological Dictionary does not offer an interpretation of this name.
Note that to an audience that was familiar with the Persian word דת, the name Dathan also looked like Their Law, and Dathan's story seemed to reflect God's attitude toward Persian Law.