The phrase "divisible by" indicates that one number can be evenly divided into another without leaving a remainder. Some synonyms for this phrase include "wholly divisible by," "completely divisible by," or "fully divisible by." Another option is to use the mathematical symbol "∣" which means "divides" or "is a divisor of." For example, instead of saying "4 is divisible by 2," you could say "2 ∣ 4." Using different synonyms or symbols can add variety to your writing and make it more concise and clear for your audience.