Alright, let's work through 87894715 times 21257030 step by step
87894715 × 21257030 = 21257030 × (87894715)
+ 21257030 × 5 that is equal 106285150
+ 21257030 × 10 that results in 212570300
+ 21257030 × 700 that is equal 14879921000
+ 21257030 × 4000 resulting in 85028120000
+ 21257030 × 90000 resulting in 1913132700000
+ 21257030 × 800000 that is equal 17005624000000
+ 21257030 × 7000000 that is equal 148799210000000
+ 21257030 × 80000000 which equals 1700562400000000

= 1868380593596450
