All statistics are based on contigs of size >= 500 bp, unless otherwise noted (e.g., "# contigs (>= 0 bp)" and "Total length (>= 0 bp)" include all contigs).
Suggestion: all assemblies contain continuous fragments of N's of length >= 10 bp. You may consider rerunning QUAST using --scaffolds (-s) option!

Assembly                    a_gigas.3  nc_genome
# contigs (>= 0 bp)         5301       1770     
# contigs (>= 1000 bp)      4378       1273     
# contigs (>= 5000 bp)      2459       1221     
# contigs (>= 10000 bp)     2015       1185     
# contigs (>= 25000 bp)     1715       1124     
# contigs (>= 50000 bp)     1520       1037     
Total length (>= 0 bp)      661278939  473689068
Total length (>= 1000 bp)   660629130  473630402
Total length (>= 5000 bp)   655930236  473505592
Total length (>= 10000 bp)  652842980  473238229
Total length (>= 25000 bp)  648159582  472201774
Total length (>= 50000 bp)  640760281  468995938
# contigs                   5301       1295     
Largest contig              5332704    5113825  
Total length                661278939  473644963
GC (%)                      43.18      42.61    
N50                         667839     707759   
N75                         332501     363449   
L50                         283        193      
L75                         635        423      
# N's per 100 kbp           52.25      49.46