21 or 35
The number is 35.
If the sum of the digits of a given number equals nine or a multiple of nine, nine is a factor of that number.
No factor of 9 has three digits. 450 is a three-digit multiple of 150 (and of 9) with a digit sum of 9.
No. To find if a number is a factor of 3, add the number's digits. If the resulting number is a multiple of 3, then the original number is a multiple of 3. In 4339, the digits of the number added together is 19, which is not a multiple of 3.
If the last two digits of your target number are a multiple of 4, 4 is a factor of the whole number.
450 or 900
If that is the case, then three is a factor of the original number.
150
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A factor (or divisor) is a number which evenly goes into the number of which it is a factor. E.g. 5, 2, 10 and 4 are factors of 20. A multiple is a number which is a whole number of times larger than the number of which it is a multiple. E.g. 4, 6, 8, 10 and so on are multiples of 2. A product is very similar to a multiple; the product of two numbers is the two multiplied together. E.g. the product of 5 and 4 is twenty, as is the product of 10 and 2.
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