Q: What two-digit prime number has the sum of its digits that is not 7 but is a multiple of 7?

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A prime number with identical digits is 11.

I believe the number you are looking for is 96.

1617 is not a prime number. The sum of its digits is a multiple of 3, so 3 is one of its factors. A prime number has exactly two factors, 1 and the number itself, so 1617 is a composite number.

The number is 875 and its prime factors are 5; 5; 5 & 7.

Start with the smallest multiple of 13 and continue with the next smallest until finding one that fits the specifications. 13, sum of digits is 1 + 3 = 4 which is not prime 26, sum of digits is 2 + 6 = 8 which is not prime 39, sum of digits is 3 + 9 = 12 which is not prime 52, sum of digits is 5 + 2 = 7 which is prime So, 52 is the smallest positive multiple of 13 for which the sum of its digits is prime.

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A prime number with identical digits is 11.

Since its digits add up to a multiple of three, it's divisible by three. That means it's not prime.

It's an odd number so it obviously can't be divided by 2. The sum of its digits (1+6+5) is a multiple of 3, so the number itself is a multiple of 3. So it's not prime.

37

I believe the number you are looking for is 96.

1617 is not a prime number. The sum of its digits is a multiple of 3, so 3 is one of its factors. A prime number has exactly two factors, 1 and the number itself, so 1617 is a composite number.

If the sum of digits of a number is a multiple of 3 then it is divisible by 3. Sum of digits of 234567 = 2+3+4+5+6+7 = 27 = 3x9 So, 234567 is not a prime number because it is divisible by 3.

The number 11 is prime and has two identical digits.

The number is 875 and its prime factors are 5; 5; 5 & 7.

Start with the smallest multiple of 13 and continue with the next smallest until finding one that fits the specifications. 13, sum of digits is 1 + 3 = 4 which is not prime 26, sum of digits is 2 + 6 = 8 which is not prime 39, sum of digits is 3 + 9 = 12 which is not prime 52, sum of digits is 5 + 2 = 7 which is prime So, 52 is the smallest positive multiple of 13 for which the sum of its digits is prime.

Because they're in multiples of three - a quick way to tell if a number is a multiple of three is to add up the digits and see if the digits add up to a multiple of three e.g 576, 5+7+6=18, 1+8=9, 9 is a multiple of three

From the sum of digits method, 711 is a multiple of 9, so no it is not prime.