How does multiplying damage work in Skyrim?

I am having trouble calculating how much damage my character can do in one attack. I get multipliers from various sources:

• 100 one-handed skill(because 100 skill lvl = 1.4x to the base damage. See the formula for some information)
• 5 perks for Armsman(double damage).
• no weapon bonus damage enchantment items.
• sneak attack (x15 with daggers).
• shrouded gloves from dark brotherhood (makes the sneak attack 30x.)
• dualwielding legendary daedric daggers(thats base damage of about 21 each).
• power attacking(double damage with 50% bonus from dual wielding perk (also does standing power attack get thrown in while sneaking?).
• getting a critical hit(double damage if I'm not mistaken).
• and if I'm not forgetting anything using the Berzerker orc power(doubles damage).

My question is, what kind of damage multiplier am I looking at here?

According to the UESP page on weapons in Skyrim, the damage formula is:

displayed damage = (base damage + smithing upgrade)
                 * (1 + 0.4 * skill/100)
                 * (1 + perk % damage boosts)
                 * (1 + % damage from items)

While wielding a daedric dagger, having 100 one handed(all perks) and 100 sneak(all perks), the daedric dagger's base damage showed as 33. From the dagger's sneak attack(only 15x damage) it caused around 500 damage. Then I applied a power attack and it caused 1,000 damage. Then my orc used berzerk and a single strike caused 2,000 damage.

I could do some more testing (like getting shroud gloves, dual wielding with a power attack doesnt do a single hit unfortunately), and having bonus one handed damage enchants(it modifies the displayed base damage btw), but I think this is enough to show that multipliers stack (15x + 2x = 30x + 2x = 60x) instead of combine(15x + 2x = 16x + 2x = 17x).