Alright, let's work through 39817123 times 40407457 step by step
39817123 × 40407457 = 40407457 × (39817123)
+ 40407457 × 3 yielding 121222371
+ 40407457 × 20 giving us 808149140
+ 40407457 × 100 that results in 4040745700
+ 40407457 × 7000 yielding 282852199000
+ 40407457 × 10000 which equals 404074570000
+ 40407457 × 800000 that is equal 32325965600000
+ 40407457 × 9000000 yielding 363667113000000
+ 40407457 × 30000000 what gives us 1212223710000000

= 1608908685486211
