CoprimeQ

CoprimeQ[n1, n2] yields True if n1 and n2 are relatively prime, and yields False otherwise.

CoprimeQ[n1, n2, ...] yields True if all pairs of the ni are relatively prime, and yields False otherwise.

Examples

Check if two numbers are coprime:

CoprimeQ[8, 15]
(* True *)

Numbers with common factor:

CoprimeQ[12, 18]
(* False *)

Multiple numbers:

CoprimeQ[3, 5, 7]
(* True *)

Please visit the official Wolfram Language Reference for more details.