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A square number has an odd number of factors, but a number with an odd number of factor pairs is nothing special.
2 cannot be a factor of an odd number, 2 must be a factor of an even number.
If you are including 1 & 19 then they are:1,3,5,7,9,11,13,15,17 & 19.Do you see how each odd number is "2" bigger than the previous one?
25 is an odd factor of 100.
25 is a odd Factor Of 100 :D
I would call an odd number factor a factor that is an odd number. I would call a number with an odd number of factors a perfect square.
The only factor of 100 that is greater than ten and odd is 25.
5 is an odd number and is a factor of 100
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There are 9 integers less than 100 that have an odd number of factors.Every factor of a number has a pair, eg 2 & 3 are a factor pair of 6; and so it would be expected that every number has an even number of factors.However, if the factor pair of a number are the same number (eg 6 & 6 are a factor pair of 36), then there will be an odd number of factors.When there is a repeated factor like this, the number is a perfect square.Thus only perfect squares have an odd number of factors.Less than 100 there are 9 perfect squares (1, 4, 9, 16, 25, 36, 49, 64 & 81) which have an odd number of factors.100 itself is a perfect square and also has an odd number of factors, but the question asked for those numbers less than 100 with an odd number of factors.
A square number has an odd number of factors, but a number with an odd number of factor pairs is nothing special.
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