Too many to list here-see below.
if its not alphanumeric, 999999 variations
It depends on whether the order of the numbers is important or not. For example, if 123456 is seen as a different code to 213456 then there are many more possible solutions.If the order is unimportant, the number of possible combinations is equal tobinomial coefficient(15,6) = 5005If the order is important, then the number of possible permutations is equal to15! = ~1.3x1012
theres only 1 number which is 123456, the least digit is 1 and the greatest is 6
-4
216
6*5*4*3*2*1=720 possible numbers
None. Extremely simple proof: To be divisible by 5 the units digit must be 5. But then it would not be divisible by 2.
Too many to list here-see below.
if its not alphanumeric, 999999 variations
There are 10000 because there is 0001 to 9999 and then there is 0000.
There are a handful of six digit numbers that have no numbers repeating. Some examples are 123456, 234567, 345678, 456789, 567012, 654321, 765432, 876543, and 987654.
No digit that is 5 places long is equal to 6 times 2 other than 12.000
6*6*3 = 108 numbers.
If no repetition, 6! ie 720; if repetition allowed, 66 ie 46656.
It depends on whether the order of the numbers is important or not. For example, if 123456 is seen as a different code to 213456 then there are many more possible solutions.If the order is unimportant, the number of possible combinations is equal tobinomial coefficient(15,6) = 5005If the order is important, then the number of possible permutations is equal to15! = ~1.3x1012
It depends on how many digits in an area code. North America (USA, Canada, etc.) uses a uniform system of 3-digit area codes, but many other countries do not. Assuming a 3-digit area code and no other restrictions other than "first digit not zero," that leaves 900 possible area codes.