Answer

Aadinath Bhagwan, also known as Rishabhdev Bhagwan, had an āyushya of 84 lakh pūrva according to Jain tradition.

Explanation

In Jain Dharma, āyushya means lifespan. The lifespan of the first Tirthankar, Shri Aadinath Bhagwan, was extremely long because He appeared in the ancient period of the current time-cycle, when human lifespans were much greater.

Takeaway

Aadinath Bhagwan is the first Tirthankar of the present Avasarpiṇī kāl, and His life marks the beginning of Tirthankar tradition in this time-cycle.