Alright, let's work through 640365 times 6609117 step by step
640365 × 6609117 = 6609117 × (640365)
+ 6609117 × 5 that results in 33045585
+ 6609117 × 60 that equals 396547020
+ 6609117 × 300 yielding 1982735100
+ 6609117 × 0000 that equals 0
+ 6609117 × 40000 that equals 264364680000
+ 6609117 × 600000 that is equal 3965470200000

= 4232247207705
