Prime Numbers

No. 5 goes into it because of the division rule of five: If it ends in zero or five, it is divisible by 5.

22 and 27 are both composite numbers. 22 is a multiple of 11 and 27 is a multiple of 3.

The prime factors of 75 are: 3, 5

The process is known as prime factorization. There are many methods to notate this. Factor trees, rainbows, continuous division, Euclid's algorithm, etc.

That depends what set of numbers you are thinking of; but in the case of the sets commonly used - integers, rational numbers, real numbers, complex numbers - such sets are closed under multiplication, meaning that you can multiply any number in the set by any number in the set, so there is nothing to stop you multiplying such a number by itself.

A prime number is a number that has only two factors which are itself and one.

To find the prime factorization, start with any two factors of 24 and keep factoring the composite factors until all factors are prime.

24

2 x 12

2 x 2 x 6

2 x 2 x 2 x 3 = 24

1, 10133.

1

All even numbers are composite numbers except for 2 itself which is a prime number.

They are: 2, 3 and 5

100 = 2*2*5*5

2 x 2 x 5 x 5

No.

189 = 3 x 3 x 3 x 7

It's composite.

Quite a few, including 24, 30, 40, 42, 54, 56, 66, 70, 78 and 88.

-2 is a composite number. A prime number is a positive integer having exactly two factors, 1 and itself. The factors of -2 are -1 x 1 x 2.

There are lots of numbers which are neither. For example, pi, -7, 0, 1, sqrt(7).

Composite. All positive, whole numbers greater than five and ending in 0, 2, 4, 5, 6 or 8 are composite.

2,800 = 2^4 * 5^2 * 7 or 2 * 2 * 2 * 2 * 5 * 5 * 7

1. 28 = 2 and 7
2. 32 = 2

The prime factors of 82 are: 2 and 41.

Yes.

7 x 19 = 133

13 is a Prime number in its own right because it has only two factors which are itself and one