My first number is the same as the fifth
My last three numbers are an arithmetic progression with +1
My third digit is x, where 1/x is undefined
Subtract me from 0 and I am negative
Only one of my digits is a one
My second number is 9 (big hint)
My first is the square root of my favorite number
My favorite blog is the one with #youcanlearnanything spam
That’s like 5 hints
That’s my password for the next blog with a secret
PS it’s a six digit number LOL
PPS (or PSS?) you don’t need my favorite number
Math we NEED to know 