89 is a Prime number between 70 and 100 that has the ones digit one greater than the tens digit.
43
Everything that has 0 as its digit can be divided by both 2, and 5 as well as many more. Therefore it cannot be a prime number.
The number you're looking for is.... 19
The number 50 is composite. Any two-digit (or more-digit) number that ends in zero can be divided evenly by 10 (and 5 and 2, for that matter). That means no two- or more-digit number ending in 0 can be prime.
6849 and 0213
31
An on-line prime number chart ended at 10007. There are many more charts available for download. So the answer is that there are many five digit prime numbers.
No because a prime number has only two factors which are itself and one as for example 19 is a prime number but 18 is a composite number because it has more than two factors.
87 is the only 2-digit number that is 6 greater and 13 less than a square, but it is not prime.
A double digit number, triple digit number........
I'm sure there are more than 2 prime numbers that are 400 digits long.
Using prime factorization, there are 2 three digit numbers with 9 factors: 512 and 768. There are no three digit numbers with 10 or more prime factors. 512=2^9 and 768=3*2^8