N = ∑(i=1 to 9) of 23^(2i+1) Find the remainder when N is divided by 25

Dividing an integer in the 74 septillion range by 25 and finding the remainder.
Stack Overflow expert and code debugger Jeremy Thompson answered a computer programming related math question March 2013 from a standpoint of reducing CPU Cycles(Heat up!)
Problem was solved without FLT or Euler Phi Totient Function! Only modular arithmetic!
Reducing Huge 9 Termed Summation Exponential Modulo 25
Fascinating Computer programming language challenge:
If the integers from 1 to 999,999 are translated to words, sorted alphabetically, and attached to each other(concatenated), what is the 33 thousandth letter?
Example 135 reads one hundred and thirty five which is 23 letters(after excising the spaces) some coders may choose to also delete all the "ands"

[@RichardCraggs]

I'm a secondary Maths teacher in the UK, loved this! Thanks!

[@MyOneFiftiethOfADollar]

Glad you enjoyed it. Was the topic something any of your students might enjoy or more of a personal interest?