Alright, let's work through 20329459 times 6437894 step by step
20329459 × 6437894 = 6437894 × (20329459)
+ 6437894 × 9 yielding 57941046
+ 6437894 × 50 which equals 321894700
+ 6437894 × 400 producing 2575157600
+ 6437894 × 9000 yielding 57941046000
+ 6437894 × 20000 that equals 128757880000
+ 6437894 × 300000 giving us 1931368200000
+ 6437894 × 0000000 that is equal 0
+ 6437894 × 20000000 giving us 128757880000000

= 130878902119346
