The number that has exactly 7 factors is a square of a Prime number. In general, a number with an odd number of factors must be a perfect square. This is because factors come in pairs, except when the number is a perfect square, where the square root is counted only once. Therefore, the only number with exactly 7 factors is the square of a prime number.
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All prime squares have exactly three factors.49 has exactly three factors: 1, 7, and 49.
A prime number has exactly two factors.
The number that has exactly 15 factors is 28. To determine the number of factors a number has, you can prime factorize the number and then add 1 to each exponent in the prime factorization and multiply these numbers together. In the case of 28, the prime factorization is 2^2 * 7^1, so the number of factors is (2+1) * (1+1) = 3 * 2 = 6. To have exactly 15 factors, the number needs to be a square of a prime number, so 28 = 2^2 * 7^1 fits this criteria.
A number has exactly three factors if and only if it is the square of a prime number.
A number that has exactly two (positive) factors is called a prime number. For instance, the only factors of 7 are 1 and 7.
729 is the second number with exactly 7.
There are an infinite number of integers with "only 7 factors". Any number which is the product of exactly 7 prime numbers.
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64 is the least number having exactly 7 factors: 1, 2, 4, 8, 16, 32, and 64.
All prime squares have exactly three factors.49 has exactly three factors: 1, 7, and 49.
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64
Any number that is the 6th power of a prime integer.
Their common factors are 1 and 7 .
It is 2^6 = 64.
A prime number has exactly two factors.