The number 0.
The divisibility rules for a prime number is if it is ONLY divisible by 1, and itself.
1
yes I believe 728393 is prime because you have to do all the divisibility rules out!
Its really easy all you have to do is divide without leaving a remainder
Simplifying fractions and finding the GCF is easy. All you have to do is put the fraction into simplest form and then put in a whole number.
all you got to do is see the amount of times the number can go into the number
No.
The divisibility rule for 22 is that the number is divisible by 2 and by 11. Divisibility by 2 requires that the number ends in 0, 2, 4, 6 or 8. Divisibility by 11 requires that the difference between the sum of the the digits in odd positions and the sum of all the digits in even positions is 0 or divisible by 11.
The formal answer is that 18 goes into the number without remainder. A simple test for divisibility by 18 is as follows: (a) the number must be even. (b) the sum of all the digits of the number must be divisible by 9. (a) ensures the number is divisible by 2 and (b) that it is divisible by 9. So, together they ensure divisibility by 2*9 = 18. Note that (b) only works with 3 and 9.
The last two digits (the tens and units) are divisible by 4.This is equivalent to the following two conditions:If the tens digit is even, the units digit must be 0, 4 or 8If the tens digit is odd, the units digit must be 2 or 6For divisibility by 9, calculate the digital root: this is the sum of all the digits in the number. Repeat with the digits of this number - and keep repeating until you are down to a single digit. It that is 9, then the number is divisible by 9 and if not, it is not.
Here is a very simple algorithm: Call your number "n". You might test divisibility by every number, starting at 2. If the first number by which a number is divisible is equal to "n", then it is a prime number. - Faster algorithms are possible; for example, you really only need to test divisibility by all numbers, up to the square root of your number "n".Here is a very simple algorithm: Call your number "n". You might test divisibility by every number, starting at 2. If the first number by which a number is divisible is equal to "n", then it is a prime number. - Faster algorithms are possible; for example, you really only need to test divisibility by all numbers, up to the square root of your number "n".Here is a very simple algorithm: Call your number "n". You might test divisibility by every number, starting at 2. If the first number by which a number is divisible is equal to "n", then it is a prime number. - Faster algorithms are possible; for example, you really only need to test divisibility by all numbers, up to the square root of your number "n".Here is a very simple algorithm: Call your number "n". You might test divisibility by every number, starting at 2. If the first number by which a number is divisible is equal to "n", then it is a prime number. - Faster algorithms are possible; for example, you really only need to test divisibility by all numbers, up to the square root of your number "n".
all numbers whose last digits are 5 and 0