23
53 is prime, and 5+3 = 8.
The largest three digit prime number whose digits are all primes is 773.
The smallest two-digit prime number whose digits themselves are prime is 23. Both 2 and 3 are prime numbers, and together they form the prime number 23.
The largest 3 digit number whose digits are all primes is 777. The largest 3 digit number with different prime digits is 753.
23
53 is prime, and 5+3 = 8.
The largest three digit prime number whose digits are all primes is 773.
The smallest two-digit prime number whose digits themselves are prime is 23. Both 2 and 3 are prime numbers, and together they form the prime number 23.
The largest 3 digit number whose digits are all primes is 777. The largest 3 digit number with different prime digits is 753.
17
The smallest prime number, of course, is 2. The smallest prime number whose digits add up to 2 is, of course, 2. The next-smallest is 11. It is left as an exercise for the reader to determine whether the other numbers whose digits add up to 2 (e.g. 101, 1001, 10001) are prime.
7777
The only two digit numbers whose digits add up to 17 are 89 and 98. Since 98 is an even number, 89 is prime.
This question doesn't quite make sense; a prime number has no factors.If you meant a prime whose digits sum to 10 it is 37.
How about: 773
I think it will be 17. The sum of digits is 8, which is the cube of 2.