Least Common Multiple of 1981 and 1989
Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Free LCM Calculator determines the least common multiple (LCM) between 1981 and 1989 the smallest integer that is 3940209 that is divisible by both numbers.
Least Common Multiple (LCM) of 1981 and 1989 is 3940209.
LCM(1981,1989) = 3940209
LCM of 1981 and 1989
Least common multiple or lowest common denominator (LCD) can be calculated in three ways;
- Least Common Multiple of 1981 and 1989 by Prime method
- Least Common Multiple of 1981 and 1989 with GCF Formula
LCM of 1981 and 1989 is 3940209
Least common multiple can be found by multiplying the highest exponent prime factors of 1981 and 1989. First we will calculate the prime factors of 1981 and 1989.
Prime Factorization of 1981
| 7 | 1981 |
| 283 | 283 |
| 1 |
Prime factors of 1981 are 7,283. Prime factorization of 1981 in exponential form is:
1981 = 71×2831
Prime Factorization of 1989
| 3 | 1989 |
| 3 | 663 |
| 13 | 221 |
| 17 | 17 |
| 1 |
Prime factors of 1989 are 3, 13,17. Prime factorization of 1989 in exponential form is:
1989 = 32×131×171
Now multiplying the highest exponent prime factors to calculate the LCM of 1981 and 1989.
LCM(1981,1989) = 32×71×131×171×2831
LCM(1981,1989) = 3940209
Factors of 1981
List of positive integer factors of 1981 that divides 1981 without a remainder.
1, 7, 283, 1981
Factors of 1989
List of positive integer factors of 1989 that divides 1989 without a remainder.
1, 3, 9, 13, 17, 39, 51, 117, 153, 221, 663, 1989
Least Common Multiple of 1981 and 1989 with GCF Formula
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 1981 and 1989, than apply into the LCM equation.
GCF(1981,1989) = 1
LCM(1981,1989) = ( 1981 × 1989) / 1
LCM(1981,1989) = 3940209 / 1
LCM(1981,1989) = 3940209
Properties of LCM 1981 and 1989
(i) The LCM of 1989 and 1981 is associative
LCM of 1981 and 1989 = LCM of 1989 and 1981
Related Least Common Multiples of 1981
Related Least Common Multiples of 1989
Frequently Asked Questions on LCM of 1981 and 1989
1. What is the LCM of 1981 and 1989?
Answer: LCM of 1981 and 1989 is 3940209.
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 1989?
Answer: Factors of 1989 are 1, 3, 9, 13, 17, 39, 51, 117, 153, 221, 663, 1989. There are 12 integers that are factors of 1989. The greatest factor of 1989 is 1989.
4. How to Find the LCM of 1981 and 1989?
Answer:
Least Common Multiple of 1981 and 1989 = 3940209
Step 1: Find the prime factorization of 1981
1981 = 7 x 283
Step 2: Find the prime factorization of 1989
1989 = 3 x 3 x 13 x 17
Step 3: Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:
LCM = 3940209 = 3 x 3 x 7 x 13 x 17 x 283
Step 4: Therefore, the least common multiple of 1981 and 1989 is 3940209.