_____________ is the factor of every number.

Hint:Before solving this question, let us know about Multiples and Factors.
MULTIPLES: Any number that can be completely divided by another number is called the multiple of the number. For example: 8 completely divisible by 4, therefore, 8 is a multiple of 4.
FACTORS: Any number that divides another number exactly is called a factor of the number.
For example: 4 completely divides 8, therefore, 4 is a factor of 8.

Complete step by step answer:
Let us now solve the question.
We know that 1 is the only number that completely divides any number, whether odd or even or prime or composite.
So, every number is divisible by 1.
In other words, we can say that every number is a multiple of 1.
Therefore, the answer to this question is 1.
Hence, the word that will fill the blank is one.
One is the factor of every number.
We can take any example for the proof of this question.
Say 62. When we will divide 62 by 1, we will get 62 as the quotient and 0 will be the denominator.
So; 62 is completely divisible by 1.
And not only 62, but every number is divisible by 1.
So, we can say that ‘one is the factor of every number.’

Note:Let us now learn about the multiplicative identity.
MULTIPLICATIVE IDENTITY: The "Multiplicative Identity" is a number that when multiplied with any number, given the number itself. Therefore, the multiplicative identity is 1, because when we multiply a number by 1, the product remains unchanged.