160 NASDAQ-100 mini futures contracts are required to hedge a portfolio that mirrors the NASDAQ-100 index.

The number of stock contracts required to hedge the portfolio is calculated as:

$\text{Number of contracts} = \beta \times \left(\frac{\text{Value of the portfolio}}{\text{Futures price} \times \text{Contract multiplier}}\right)$

Since the portfolio perfectly mirrors the index, the beta of the given portfolio is considered 1.

The contract multiplier = $20 \times 5,056 = 101,120$

$\text{Number of contracts} = 1 \times \left(\frac{16,165,000}{101,120}\right) = 159.8 \approx 160 \text{ contracts}$