04,14,24,34,40,41,42,43,44,45,46,47,48,49,54,64,74,84,94.... OR 19 Digits
172
9 Digit
If the number can contain repeated digits, the answer is 800000. Without repetition, there are 483840.
874
8 digits
5. Count the number of digits from the first non-zero digit to the last non-zero digit.
10
The number of digits in a valid credit card can change depending upon the type of card. Mastercard and VISA use a 16 digit system, while others including American Express use a 15 digit system.
It will contain at least 12 digits
16 digit number
Six.