No problem, we've got 21345431 and 78056939 to multiply
21345431 × 78056939 = 78056939 × (21345431)
+ 78056939 × 1 giving us 78056939
+ 78056939 × 30 resulting in 2341708170
+ 78056939 × 400 that equals 31222775600
+ 78056939 × 5000 that equals 390284695000
+ 78056939 × 40000 yielding 3122277560000
+ 78056939 × 300000 giving us 23417081700000
+ 78056939 × 1000000 yielding 78056939000000
+ 78056939 × 20000000 producing 1561138780000000

= 1666159005495709
