cipher - Room 2 of the Maze

Still excited about your quick triumph over Room 1, you head straight for the suspended note and read it:

Congratulations on making it through the warm-up to Room 2. From here on out, getting the answer from Key 2 will now require the use of the answer from the previous room in addition to Key 1. You will be unable to get the correct answer without the use of these two values (though their roles in the solution process will differ between rooms). In case you forget, we will always include the answer from the previous room in our letter.
This room will be more challenging than the first, Key 2 has been encrypted, and Key 1 seems to be of no help. You'll need to use the answer from the previous room up front. Good Luck!!

Key 1: Key 2 is much more than the sum of its parts.
Key 2: UAST OIGT UQH VBPU PMBNQPXFAGBHT. UMIG PVTHPX UIQM PI PTH. PUTH FIID PI DTX IHT

For those who want to start from the beginning, search for Room 1 of the Maze. The answer for the previous room, for those who forgot or who want to join in starting in this room, is below.

You notice that the keypad in this room has only the digits 0-9 as well as the usual Enter button. What do you enter to move on to the next room in the Maze?

Answer from Previous Room:

ANKARATURKEY

EDIT: Halfway through your calculations, a small portal opens in the center of the room and a note materializes from it. You hurriedly grasp it and read its contents:

We hear that your kind is quite fond of the number 10; something about the number of digits on your extremities. We've heard that some of your kind have learned to use other numbers in it's place and translate between them; hopefully you are one of these. If it is any consolation, we have 349 fblthps on each of our kjaposenjfq, so you can imagine what math is like on our planets!

This room has now been solved. Here is Room 3

Answer

Solving Key 2 as a keyed Caesar cipher with the key being the answer from room 1, you get:

FAVE SOME FUN WITF TRIBUTYLAMINE. FROM TWENTY FOUR TO TEN. TFEN LOOK TO KEY ONE

The H's in the string are incorrectly coded to F's - they should be Y's in the coded version but they are presented as U's.

H being coded to F in the string could mean we should also code it to F in the chemical (C12F27N instead of C12H27N)

EDITS:

Based on the new info, we need to convert C12F27N from base 24 to base 10, which gives 2302070591.

Then, the sum of its parts gives the answer as:

29