How many stone blocks can you mine with 36 stone pickaxes?

4962 blocks- enough to mine a solid 17x17x17 cube.

The most efficient repair possible involves two tools with a total durability of 126. This gives the maximum possible bonus of 6 extra uses.

With 36 pickaxes you will make 35 repairs.

35*6=210 bonus from repairs

The 36 pickaxes themselves will mine 132 blocks each.

36*132= 4752 blocks

4752+210= 4962 blocks mined in total.