How many total perks are there in Skyrim?

How many total perks are in Elder Scrolls: Skyrim and does it vary for different skills?

There are a total of 251 perks.

Path of Might – 91

• Smithing: 10
• Heavy Armor: 12
• Block: 13
• Two-handed: 19
• One-handed: 21
• Archery: 16

Path of Shadow – 74

• Light Armor: 10
• Sneak: 13
• Lockpicking: 11
• Pickpocket: 12
• Speech: 13
• Alchemy: 15

Path of Sorcery – 86

• Illusion: 13
• Conjuration: 16
• Destruction: 17
• Restoration: 13
• Alteration: 14
• Enchanting: 13

There are also a number of other abilities that function more or less like perks, found by completing certain quests or objectives. These are free: you don't have spend points on them.