Answer
680 is not perfect because:
1 + 2 + 4 + 5 + 8 + 10 + 17 + 20 + 34 + 40 + 68 + 85 + 136 + 170 + 340 ≠ 680
Related links:
Answer
680 is not perfect because:
1 + 2 + 4 + 5 + 8 + 10 + 17 + 20 + 34 + 40 + 68 + 85 + 136 + 170 + 340 ≠ 680