Greatest Common Factor of 1981 and 1985

Greatest common factor or Greatest common divisor (GCD) can be calculated in following way;

• Greatest Common Factor of 1981 and 1985 by prime factorization method
• Greatest Common Factor of 1981 and 1985 by matching factors method

Prime Factorization of 1981

Prime factors of 1981 are 7,283. Prime factorization of 1981 in exponential form is:

1981 = 7¹×283¹

Prime Factorization of 1985

Prime factors of 1985 are 5,397. Prime factorization of 1985 in exponential form is:

1985 = 5¹×397¹

∴ So by taking common prime factors GCF of 1981 and 1985 is 1

Factors of 1981

List of positive integer factors of 1981 that divides 1981 without a remainder.

1,7,283,1981

Factors of 1985

List of positive integer factors of 1985 that divides 1985 without a remainder.

1,5,397,1985

Greatest Common Factor

We found the factors and prime factorization of 1981 and 1985. The biggest common factor number is the GCF number.
So the greatest common factor 1981 and 1985 is 1.

Also check out the Least Common Multiple of 1981 and 1985

(i) The GCF of 1981 and 1985 is associative

GCF of 1981 and 1985 = GCF of 1985 and 1981

1. What is the GCF of 1981 and 1985?

Answer: GCF of 1981 and 1985 is 1.

2. What are the Factors of 1981?

Answer: Factors of 1981 are 1, 7, 283, 1981. There are 4 integers that are factors of 1981. The greatest factor of 1981 is 1981.

3. What are the Factors of 1985?

Answer: Factors of 1985 are 1, 5, 397, 1985. There are 4 integers that are factors of 1985. The greatest factor of 1985 is 1985.

4. How to Find the GCF of 1981 and 1985?

Answer:

Greatest Common Factor of 1981 and 1985 = 1

Step 1: Find the prime factorization of 1981

1981 = 7 x 283

Step 2: Find the prime factorization of 1985

1985 = 5 x 397

Step 3: Multiply those factors both numbers have in common in steps i) or ii) above to find the gcf:

GCF = = 1

Step 4: Therefore, the greatest common factor of 1981 and 1985 is 1