To convert 6 km² 23456m² to km², we first need to convert 23456m² to km².

1 km² is equal to 1,000,000 m². Therefore, to convert 23456m² to km², we divide by 1,000,000:

23456m² / 1,000,000 = 0.023456 km²

Now we add the original 6 km² to get the final result:

6 km² + 0.023456 km² = 6.023456 km²

Therefore, 6 km² 23456m² is equal to 6.023456 km².