It is: 59
what number is prime to 40 29 - it's a prime number (divisible only by 1 and itself) and if you sum the two digits 2 + 9 = 11
If you multiply two prime numbers, the product (result) will be a composite number, not a prime number. A prime number has exactly two factors, 1 and itself. The product of two prime numbers will have those two numbers as factors, as well. The sum of two prime numbers might be prime if one of those two numbers is 2, the only even prime number, but otherwise it will not be a prime because two odd numbers will have an even sum, which means it is divisible by 2. Examples: 2 + 3 = 5 (prime) 3 + 7 = 10 (not prime) 13 + 17 = 30 (not prime) If you multiply two prime numbers, the sum of the digits of the product might or might not be prime. Examples: 2 x 7 = 14, sum of digits is 5 (prime) 2 x 11 = 22, sum of digits is 4 (not prime) 3 x 5 = 15, sum of digits is 6 (not prime) 3 x 7 = 21, sum of digits is 3 (prime) 5 x 7 = 35, sum of digits is 8 (prime)
There are two numbers that satisfy the criteria. 38 and 83
The only two digit numbers whose digits add up to 17 are 89 and 98. Since 98 is an even number, 89 is prime.
There are actually three valid answers: 17, 53, and 71 All are prime and all have digits adding to 8.
Two-digit prime numbers whose digits add up to 10 are:193773
The number 11 is prime and has two identical digits.
No two digit prime number exists that is a multiple of 7. All two digit numbers that are multiples of 7 are compositenumbers.