For such enormous numbers, even Karatsuba's algorithm is too slow. A real breakthrough came in 1971 with the work of the German mathematicians Arnold Schönhage and Volker Strassen.

Prime numbers are whole numbers greater than 1 that are not divisible by any whole number other than 1 and itself. The first few are 2, 3, 5, 7, 11, 13 … ...