Here's the full set of possible answers:
192
219
267
273
327
Enjoy!
A delectable number has nine digits, using the numbers 1-9 once in each digit. The first digit of a delectable number must be divisible by one. The first and second digits must be divisible by two, the first through third must be divisible by three, etc. There has only been one delectable number discovered: 381654729.
0.123456789
The smallest number that someone can get using the 91764 digits is 14679. The secret is to arrange the digits from the least number to their greatest number.
This is a factorial problem. The first number can be any of ten digits, the second any of nine (because you can't repeat a digit), the third any of eight and the fourth any of the remaining 7 digits. 10x9x8x7=5040 combinations.
Standard Form
A delectable number has nine digits, using the numbers 1-9 once in each digit. The first digit of a delectable number must be divisible by one. The first and second digits must be divisible by two, the first through third must be divisible by three, etc. There has only been one delectable number discovered: 381654729.
0.123456789
Assuming you can repeat digits (like the number 1228 for example), there are 84 = 4096.If you can't repeat digits then it is equivalent to 8!/4! = 1680.
The number 100, using digits 0 thru 8, would equal the number 81 using digits 0 thru 9. 1x92 + 0x91 + 0x90 which is 1x9x9 + 0x9 + 0x1
987,654,321
0.123456789
The smallest number that someone can get using the 91764 digits is 14679. The secret is to arrange the digits from the least number to their greatest number.
This is a factorial problem. The first number can be any of ten digits, the second any of nine (because you can't repeat a digit), the third any of eight and the fourth any of the remaining 7 digits. 10x9x8x7=5040 combinations.
Standard Form
9,999,876 is the greatest seven-digit number using four different digits.
You get the largest number if you sort the digits, from largest to smallest.
The first digit can be 0 through 9, ten possibilities. Having selected the first digit, you have 9 digits to pick from the second digit. Having selected the second digit, you have 8 digits to pick from the third digit. Hence total possibilities = 10 x 9 x 8 = 720