Alright, let's work through 20420820 times 52110458 step by step
20420820 × 52110458 = 52110458 × (20420820)
+ 52110458 × 0 what gives us 0
+ 52110458 × 20 that results in 1042209160
+ 52110458 × 800 yielding 41688366400
+ 52110458 × 0000 producing 0
+ 52110458 × 20000 that is equal 1042209160000
+ 52110458 × 400000 which equals 20844183200000
+ 52110458 × 0000000 what gives us 0
+ 52110458 × 20000000 yielding 1042209160000000

= 1064138282935560
