1,330,560
Seven
997. To test that 997 is prime, we only need to test values up [997^.5], so up to 31. Using divisibility rules, we can immediately eliminate several possible divisors. Rule for 7: If you have a number, separate the last digit from the proceeding ones. Subtract twice the last digit from the number created from slicing off the last part. if that's divisible by seven, the whole number is. For example, take 343. 34-2(3) is 28, which is divisible by 7, so 343 is divisible by 7 Rule for 3: sum of digits is divisible by 3. Rule for 2: last digit is divisible by 2. Rule for 2^n: last n digits form a number that is divisible by 2^n Rule for 5: last digit is 5 or 0. Rule for 11: Difference of alternating sums of the digits, 432113 is divisible by 11 because (4+2+1)-(3+1+3) is divisible by eleven. Rule for 9: sum of digits is divisible by 9. Trying 13, 17, 19, 23, and 29, we see these all fail. So 997 is indeed prime.
No, it is not a prime number because it can be divided by 9 to get 3. A prime number is only divisible by itself and one.
6312345, to the nearest hundred thousand.
The prime number is seven, as it's only divisible by one and itself.Same goes for 11, 13, 17, and so on.
41
4,555,558
58.5
To find out if a number is divisible by seven, take the last digit, double it, and subtract it from the remaining digits of the number.If the result is divisible by 7 (including zero), then the original number is divisible by seven. If the new number is still too big, you can apply the rule again.Example: 406.First, double the last digit, 6. (6 times 2 equals 12.)Second, subtract that number from the remaining digits. (12 subtracted from 40 equals 28.)Third, if the result is divisible by seven, the whole number is. (7 divides equally into 28.)Thus, since the result is divisible by seven, we can conclude that 406 is divisible by seven.If the result is still to big, repeat this procedure.Example: 7,805.Double the last digit, (makes 10,) subtract it from remaining digits, (780 minus 10 equals 770.)770 is still to big a number to easily determine whether it is divisible by seven, so it is best to repeat the procedure, like so:Double the last digit, which is a little weird since the last digit is zero, but 0 plus 0 still equals zero. (0 times 2 equals zero.) Subtract from remaining digits, (77 minus 0 equals 77.)77 is divisible by 7, so we can conclude that 7,805 is divisible by seven.
When a number is a multiple of seven it is also divisible by seven.
510 is not divisible by seven.
To find out if a number is divisible by seven, take the last digit, double it, and subtract it from the rest of the number.Example: If you had 203, you would double the last digit to get six, and subtract that from 20 to get 14. If you get an answer divisible by 7 (including zero), then the original number is divisible by seven. If you don't know the new number's divisibility, you can apply the rule again. Source~http://mathforum.org/k12/mathtips/division.tips.html But with incrediby large numbers you're just better off just dividing to see.
The smallest number divisible by eight seven and five is 280.
there is one for seven although its not very useful. take the last digit trunccate it and double it then subtract the rest. If the resulting number is divisible by seven, so was the origanil
Seven
There is an infinite number of numbers that are not divisible by seven!
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.