168 (one hundred [and] sixty-eight) is the natural number following 167 and preceding 169.

It is the number of hours in a week, or 7×24 hours. 168 is the fourth Dedekind number, and the 128th composite number.

168 is the fourth Dedekind number, and one of sixty-five idoneal numbers. It is one less than a square (13²), equal to the product of the first two perfect numbers

There are 168 primes less than 1000.

The 128th composite number is 168, one of a few numbers ${\displaystyle n}$ in the list of composites whose indices are the product of strings of digits of ${\displaystyle n}$ in decimal representation.

The first nine ${\displaystyle n}$ with this property are the following:

The next such number is 198 where 19 × 8 = 152. The median between twenty-one integers [48, 68] is 58, where 148 is the median of forty-one integers [168, 128].

For the Euler totient ${\displaystyle \varphi (n)}$ there is ${\displaystyle \varphi (168)=48}$, where ${\displaystyle \varphi (48)=16}$ is also equivalent to the number of divisors of 168; only eleven numbers have a totient of 48:{65, 104, 105, 112, 130, 140, 144, 156, 168, 180, 210}.