Pūrva

84,00,000 years make one pūrvāṅga, and 84,00,000 pūrvāṅga make one pūrva: 70,560,000,000,000 years, written out in full because the texts write it out in full.

This is the unit the tradition actually uses. Bharata Cakravartī ruled for a span measured in pūrva. Ṛṣabhanātha, the first Tīrthaṅkara of this half-cycle, lived 84 lakh pūrva, which is about 5.9 × 10²⁰ years.

For scale: one pūrva is roughly five thousand times the present age of the universe. And there are thirteen larger named units still above it on this ladder.

Each step from here multiplies by 84 lakh again, and each has an -āṅga partner one 84-lakhth its size, giving twenty-eight named units in all.