Alright, let's work through 64289878 times 6677290 step by step
64289878 × 6677290 = 6677290 × (64289878)
+ 6677290 × 8 resulting in 53418320
+ 6677290 × 70 resulting in 467410300
+ 6677290 × 800 that results in 5341832000
+ 6677290 × 9000 resulting in 60095610000
+ 6677290 × 80000 giving us 534183200000
+ 6677290 × 200000 producing 1335458000000
+ 6677290 × 4000000 producing 26709160000000
+ 6677290 × 60000000 which equals 400637400000000

= 429282159470620
