Alright, let's work through 46877987 times 81321636 step by step
46877987 × 81321636 = 81321636 × (46877987)
+ 81321636 × 7 yielding 569251452
+ 81321636 × 80 that is equal 6505730880
+ 81321636 × 900 what gives us 73189472400
+ 81321636 × 7000 what gives us 569251452000
+ 81321636 × 70000 what gives us 5692514520000
+ 81321636 × 800000 yielding 65057308800000
+ 81321636 × 6000000 that is equal 487929816000000
+ 81321636 × 40000000 producing 3252865440000000

= 3812194595226732
