The Luhn algorithm is commonly used simple method to minimise typos in credit card numbers.
These example numbers have a valid Luhn checksum:
4111111111111111
5555555555554444
These example numbers are invalid:
13245674
7992739871311111
How many of the below numbers have a valid Luhn checksum?
791947779410
223082153551
611666145821
794235010051
616287113937
724549167320
647632969758
317331776148
949183117216
40480279449
750760398084
64263669287
410884491574
875414458836
871211445515
483838182873
275472644968
474910584091
610539110790
113853353331