No problem, we've got 1661 and 6258 to multiply
1661 × 6258 = 6258 × (1661)
+ 6258 × 1 giving us 6258
+ 6258 × 60 that equals 375480
+ 6258 × 600 which equals 3754800
+ 6258 × 1000 resulting in 6258000

= 10394538
