Greatest common divisor and least common multiple for two integers (Euclidean GCD).
Both inputs must be positive integers (non‑integer text fails). GCD uses the Euclidean algorithm on floored absolutes; LCM = a ÷ GCD × b (product order avoids overflow slightly better than a×b÷GCD in theory).
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.