There is nothing strange about the number 13. It is a natural number. It is a Prime number but there are an infinite amount of those.
There are some silly superstitions associated with it.
Chat with our AI personalities
Thirteen = 13
Mathematically, the opposite of a number would be its negative. Rhetorically, the opposite of thirteen is "not thirteen".
No.
Thirteen-ninths as a mixed number is 14/9
Thirteen septillion.