Math - multiplicative persistence order 10 in base 10

• 10 digits:3778888999 -> 438939648 -> 4478976 -> 338688 -> 27648 -> 2688 -> 768 -> 336 -> 54 -> 20 -> 0 [10]
• 10 digits:4677888999 -> 438939648 -> 4478976 -> 338688 -> 27648 -> 2688 -> 768 -> 336 -> 54 -> 20 -> 0 [10]
• 13 digits:3888888888889 -> 231928233984 -> 4478976 -> 338688 -> 27648 -> 2688 -> 768 -> 336 -> 54 -> 20 -> 0 [10]
• 13 digits:4688888888889 -> 231928233984 -> 4478976 -> 338688 -> 27648 -> 2688 -> 768 -> 336 -> 54 -> 20 -> 0 [10]