There are 81 Categories of Devotional Service

[Bhava dasa (ACBSP)]

“Devotional service in the modes of ignorance, passion and goodness can be divided into eighty-one categories.

1. There are [nine] different devotional activities, such as hearing, chanting, remembering, worshiping, offering prayer, rendering service and surrendering everything,
2. and each of them can be divided into three qualitative categories. There is hearing in the mode of passion, in the mode of ignorance and in the mode of goodness. Similarly, there is chanting in the mode of ignorance, passion and goodness, etc.
3. Three multiplied by nine equals twenty-seven, and
4. when again multiplied by three it becomes eighty-one. One has to transcend all such mixed materialistic devotional service in order to reach the standard of pure devotional service, as explained in the next verses [SB 3.29.11…].”

[ 03. Śrīmad-Bhāgavatam (Bhāgavata Purāṇa) / Canto 3: The Status Quo / SB 3.29: Explanation of Devotional Service by Lord Kapila / SB 3.29.10 / PURPORT]