akṣauhiṇī f. an army consisting of ten anikinis, or 21, 870 elephants, 21, 870 chariots, 65, 610 horse, and 109, 350 foot. (Since an anikini consists of 27 vāhinis, and 27 is the cube of 3, akṣauhiṇī may be a compound of 2. akṣa and vāhini 
• or it may possibly be connected with 1. akṣa, axle, car.) 
 

Sarvastivada Abhidharma, Sanskrit-English Glossary, by Bhikkhu KL Dhammajoti