Alright, let's work through 99389293 times 18431507 step by step
99389293 × 18431507 = 18431507 × (99389293)
+ 18431507 × 3 yielding 55294521
+ 18431507 × 90 giving us 1658835630
+ 18431507 × 200 giving us 3686301400
+ 18431507 × 9000 resulting in 165883563000
+ 18431507 × 80000 which equals 1474520560000
+ 18431507 × 300000 what gives us 5529452100000
+ 18431507 × 9000000 that results in 165883563000000
+ 18431507 × 90000000 yielding 1658835630000000

= 1831894449654551
