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The number 1 is not a prime number. A prime number by definition is a positive integer greater than 1 that is evenly divisible by only itself and 1.

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Two is a prime number. Two is the smallest prime number and the only even prime number, since all other even numbers divide by two.

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Yes, 2 is a prime number. In fact, 2 is the only even number that is prime. A prime number is a number that has only two factors, the number 1 and itself.

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Nine is not a prime number. It is a composite number, because it has more than two factors. A prime number is only divisible by one and by itself, and nine is divisible by one and by nine, but it is also divisible by the number three.

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The number zero is not a prime number. By definition, a prime number dictates that the number must be a whole number greater in value than one and must be divisible by only itself and one.

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The number 19 is the eighth prime number. A prime number is a positive, whole number that is only divisible by one and itself. Nineteen is also the seventh Mersenne prime exponent, which is a prime number that is one less than a power of two.

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One is not a prime number because the definition of a prime number is any number that is greater than one that is only divisible by one and itself. Since one is of course not greater than one, it does not fit the definition of a prime number.

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A factor tree is a diagram that shows the breakdown of a number into its prime factors. This diagram holds a pattern similar to a family tree, with a line between each factor and its factors.

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Numbers that multiply to give you a larger number are called factors. Use a factor tree for an easy way to factor larger numbers.

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The prime factors of 12 are 2 and 3. A prime number is a number greater than 1 that cannot be divided by any number except itself and 1. Both 2 and 3 are prime factors of 12 because they are prime numbers that can be divided into 12 with nothing remaining.