What is the next number?

𝐭𝐰𝐞𝐧𝐭𝐲, 𝐭𝐡𝐢𝐫𝐭𝐲, 𝐟𝐨𝐫𝐭𝐲, 𝐟𝐢𝐟𝐭𝐲, ...

• sixty
• sixteen
• seventeen