Ajitnath is the 2nd Tirthankar. In Jain scriptures his lifespan is given as 72 lakh purva. That means he was born in Ayodhya on the tenth day of Magha (bright half), and he lived for 72 lakh purva. In traditional Jain cosmology those time units are extremely large, and there isn’t a precise modern-year equivalent given consistently across traditions. So, while the text says “72 lakh purva” for his life span, converting that to exact modern years isn’t straightforward and varies by Digambara/Shvetambara interpretations. You can read more about his story and the traditional time-scale here and about the time-unit details here .