Here's the answer:

Answer: 602317

Let's analyze the pattern step by step based on the given examples:

1. 8 + 2 = 16106:

   • $16$ is $8\times 2$,
   • $10$ is $8+2$,
   • $6$ is $8-2$.

2. 5 + 4 = 2091:

   • $20$ is $5\times 4$,
   • $9$ is $5+4$,
   • $1$ is $5-4$.

3. 9 + 6 = 54153:

   • $54$ is $9\times 6$,
   • $15$ is $9+6$,
   • $3$ is $9-6$.

4. 7 + 5 = 35122:

   • $35$ is $7\times 5$,
   • $12$ is $7+5$,
   • $2$ is $7-5$.

For $20+3$:

• $20\times 3=60$,
• $20+3=23$,
• $20-3=17$.

Final result: 602317.