Are there any prime numbers that end in 5?

5

Based on the definition of prime numbers, a prime number has no factors other than 1 and itself. Thus 5 is itself prime!

And by definition, 5 is the ONLY prime number ending in 5, as all larger numbers ending in 5 are multiples of 5.

The only other single-digit prime number which is also the only prime number ending in that digit is 2. Both 3 and 7 can be the final digit of a larger prime number - 13 and 17 are examples.

I'm no math surgeon, but any natural number ending with 5 is always a multiple of 5. You can't state this with any other non-zero number. For example, 3 is not a multiple of all numbers ending with 3: 13, 23, 43, etc.

This is because 5 also represents half the digits of our 10-digit numbering system. Therefore, 5 has an imaginary value of a half. Not as 1-over-2 but as increments of half of our numbering system of 10.

For example, 15 is the product of 3 times half the digits of our numbering system (5), and 35 is 7 times half the digits. Therefore, any number ending with 5 can't be prime because it's also the product of an odd number multiplied with half the digits in our numbering system (5). I now feel dumber.

"any natural number ending with 5 is always a multiple of 5. You can't state this with any other non-zero number."
With notable exceptions, 1 & 2.