How many 6's are in 27?

You have been challenged by a friend to make the number 27 using the digit 6 (as many times as you want). What is the minimum number of 6's that is required?

Allowed operations:

• $+, -, \times, \div, \sqrt{ \cdot }$
• Brackets
• Factorial
• Power / Exponentiation
• Concatenation of 6's in the expression

Disallowed operators. Everything else, including but not limited to:

• Flipping the 6 into a 9
• Decimal points (since you need a concatenate a 0)
• Other mathematical operators like cube roots

An example of how to use these operators is using 4's to create 28 would be $28=4 \times (4+\sqrt{4}+(4 \div 4))$ , which uses five 4's, but you can also do this with two 4's as follows: $28=4!+4$ .