Not all of them are.
7777
1, 2, 3, 5, 6, 7 and 9.
There are 282 such numbers.
13
420
The smallest 3-digit multiple of 7 is 105 = 15*7 The largest 3-digit multiple of 7 is 994 = 142*7 So there are 142-14 = 128 3-digit multiples of 7, ie 128 3-digit numbers that are divisible by 7.
There aren't any digits between 6 and 7 that are divisible by 4. There aren't any whole numbers between 6 and 7, period.
630 is divisible by...2 or 3 or 5 or 6 or 7 or 9. your welcome
7777
There are no single-digit numbers divisible by 630. 630 is divisible by 1, 2, 3, 5, 6, 7 and 9.
1, 2, 3, 5, 6, 7 and 9.
13
There are 282 such numbers.
420
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.
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.
A very unique number; it is divisible by each single digit number except 5 and 7.