Alright, let's work through 21378520 times 45010639 step by step
21378520 × 45010639 = 45010639 × (21378520)
+ 45010639 × 0 which equals 0
+ 45010639 × 20 producing 900212780
+ 45010639 × 500 which equals 22505319500
+ 45010639 × 8000 what gives us 360085112000
+ 45010639 × 70000 producing 3150744730000
+ 45010639 × 300000 yielding 13503191700000
+ 45010639 × 1000000 which equals 45010639000000
+ 45010639 × 20000000 that is equal 900212780000000

= 962260846074280
