Alright, let's work through 63972379 times 87700897 step by step
63972379 × 87700897 = 87700897 × (63972379)
+ 87700897 × 9 which equals 789308073
+ 87700897 × 70 that results in 6139062790
+ 87700897 × 300 that equals 26310269100
+ 87700897 × 2000 giving us 175401794000
+ 87700897 × 70000 that results in 6139062790000
+ 87700897 × 900000 that is equal 78930807300000
+ 87700897 × 3000000 that is equal 263102691000000
+ 87700897 × 60000000 that is equal 5262053820000000

= 5610435021523963
