There are 6.
They are:
15,45,75,51,54,57.
If you want to include negative numbers (i.e. -15 etc...) then you can double the answer.
None. 3 digit numbers are not divisible by 19 digit numbers.
one 5 all others are divisible by 5 at least
Best way to work this out: find the highest number below 10,000 that is divisible by 7 (9,996) and divide that by 7 (1,428). 1,428 is the amount of one-, two-, three- and four-digit numbers divisible by 7. Now find the number of one-, two- and three-digit numbers divisible by 7 (which is 994/7 = 142) and subtract this number from 1,428, giving us 1,286.
There are 4,500 such numbers. One of them is 5646
There are 4 such numbers (8, 48, 80, 88).
None. 3 digit numbers are not divisible by 19 digit numbers.
No one-digit numbers are divisible by 10. 10 is divisible by 1, 2 and 5.
one 5 all others are divisible by 5 at least
Best way to work this out: find the highest number below 10,000 that is divisible by 7 (9,996) and divide that by 7 (1,428). 1,428 is the amount of one-, two-, three- and four-digit numbers divisible by 7. Now find the number of one-, two- and three-digit numbers divisible by 7 (which is 994/7 = 142) and subtract this number from 1,428, giving us 1,286.
There are 4,500 such numbers. One of them is 5646
All 2 digit numbers are divisible by 7: it is simply that some of the quotients are not whole numbers. 10/7 = 1 3/7 99/7 = 14 1/7 So the number of 2-digit numbers which are evenly divisible by 7 are 14-1 = 13.
There are 4 such numbers (8, 48, 80, 88).
1234
10977120 would be one. There are several.
When the last digit is zero. All whole numbers of more than one digit and with a last digit of 0, 2, 4, 5, 6 or 8 are divisible by another number. Numbers ending with the other digits, 1, 3, 7 and 9, might be divisible by another number, and they might not.
Only one positive prime number has a 5 in the ones digit. That prime number is 5. All other numbers with a 5 in the ones digit are composite because they will be divisible by 5.
There are many numbers matching this criteria -- 500 to be exact. 1020 is the smallest one. 9996 is the largest.