Power of Two - Pattern

If $n$ is a power of two, you can divide it by $2$ repeatedly until you reach $1$. At each step, there's no remainder.

For example, $16 \div 2 = 8$, $8 \div 2 = 4$, $4 \div 2 = 2$, $2 \div 2 = 1$. All divisions are exact (remainder $0$).

But if you try this with $6$: $6 \div 2 = 3$, then $3 \div 2 = 1$ with remainder $1$. That remainder tells you $6$ is not a power of two.