Created By : Jatin Gogia
Reviewed By : Rajasekhar Valipishetty
Last Updated : Apr 06, 2023
Free LCM Calculator determines the least common multiple (LCM) between 688 and 690 the smallest integer that is 237360 that is divisible by both numbers.
Least Common Multiple (LCM) of 688 and 690 is 237360.
LCM(688,690) = 237360
Least common multiple or lowest common denominator (LCD) can be calculated in three ways;
Least common multiple can be found by multiplying the highest exponent prime factors of 688 and 690. First we will calculate the prime factors of 688 and 690.
Prime Factorization of 688
2 | 688 |
2 | 344 |
2 | 172 |
2 | 86 |
43 | 43 |
1 |
Prime factors of 688 are 2,43. Prime factorization of 688 in exponential form is:
688 = 24×431
Prime Factorization of 690
2 | 690 |
3 | 345 |
5 | 115 |
23 | 23 |
1 |
Prime factors of 690 are 2, 3, 5,23. Prime factorization of 690 in exponential form is:
690 = 21×31×51×231
Now multiplying the highest exponent prime factors to calculate the LCM of 688 and 690.
LCM(688,690) = 24×31×51×231×431
LCM(688,690) = 237360
Factors of 688
List of positive integer factors of 688 that divides 688 without a remainder.
1, 2, 4, 8, 16, 43, 86, 172, 344, 688
Factors of 690
List of positive integer factors of 690 that divides 690 without a remainder.
1, 2, 3, 5, 6, 10, 15, 23, 30, 46, 69, 115, 138, 230, 345, 690
The formula of LCM is LCM(a,b) = ( a × b) / GCF(a,b).
We need to calculate greatest common factor 688 and 690, than apply into the LCM equation.
GCF(688,690) = 2
LCM(688,690) = ( 688 × 690) / 2
LCM(688,690) = 474720 / 2
LCM(688,690) = 237360
(i) The LCM of 690 and 688 is associative
LCM of 688 and 690 = LCM of 690 and 688
1. What is the LCM of 688 and 690?
Answer: LCM of 688 and 690 is 237360.
2. What are the Factors of 688?
Answer: Factors of 688 are 1, 2, 4, 8, 16, 43, 86, 172, 344, 688. There are 10 integers that are factors of 688. The greatest factor of 688 is 688.
3. What are the Factors of 690?
Answer: Factors of 690 are 1, 2, 3, 5, 6, 10, 15, 23, 30, 46, 69, 115, 138, 230, 345, 690. There are 16 integers that are factors of 690. The greatest factor of 690 is 690.
4. How to Find the LCM of 688 and 690?
Answer:
Least Common Multiple of 688 and 690 = 237360
Step 1: Find the prime factorization of 688
688 = 2 x 2 x 2 x 2 x 43
Step 2: Find the prime factorization of 690
690 = 2 x 3 x 5 x 23
Step 3: Multiply each factor the greater number of times it occurs in steps i) or ii) above to find the lcm:
LCM = 237360 = 2 x 2 x 2 x 2 x 3 x 5 x 23 x 43
Step 4: Therefore, the least common multiple of 688 and 690 is 237360.