What is the number which is listed as the first ingredient on some bottles? September 21, 2020 19:36 This is a formula number, allowing us to more easily identify which bottle contains which formula. Related articles What is “angel dusting”? Do you use dimethicone in your products? Does AlumierMD use synthetic dyes in their products? Can I mix my AlumierMD sunscreen with makeup or other skincare products before applying it to my face?