# What is a Finale Number™?

This is in the spirit of the What is a Word/Phrase™ series started by JLee with Number version puzzles.

If a number conforms to a special rule, I call it a Finale Number™.
Use the following examples below to find the rule.

Finale Numbers™ Not Finale Numbers™
28 30
55 53
388 776
514 207
982 984
1765 1763
4978 9956
6040 3020
8110 8112
19999 19997

And, if you want to analyze, here is a CSV version:

Finale Numbers™,Not Finale Numbers™
28,30
55,53
388,776
514,207
982,984
1765,1763
4978,9956
6040,3020
8110,8112
19999,19997


A Finale Number™ is a number such that,

When you add its digits, add the digits of that result, and add the digits of that result and so on, you finish with $$1$$. This is called the digital root of a number. (Finale numbers™ have digital root $$1$$)

Finale Numbers™:

$$19999\rightarrow 1+9+9+9+9=37$$
$$37\rightarrow 3+7=10$$
$$10\rightarrow 1+0=1$$

$$8110\rightarrow 8+1+1+0=10$$
$$10\rightarrow 1+0=1$$

$$4978\rightarrow 4+9+7+8=28$$
$$28\rightarrow 2+8=10$$
$$10\rightarrow 1+0=1$$

Not Finale Numbers™:

$$19997\rightarrow 1+9+9+9+7=35$$
$$35\rightarrow 3+5=8$$

$$3020\rightarrow 3+0+2+0=5$$

$$8112\rightarrow 8+1+1+2=12$$
$$12\rightarrow 1+2=3$$

This is equivalent to: (thanks @athin!)

A Finale Number™ has a remainder of $$1$$ when divided by $$9$$.

• Actually, it is equivalent to: "jura gur ahzore vf qvivqrq ol avar, gur erzvaqre jvyy or bar". :) Sep 6, 2019 at 3:51
• Looks so! rot13(Vs lbh trg a ol qbvat guvf gur ahzore zhfg or a zbq avar evtug?)
– user47134
Sep 6, 2019 at 4:15
• yep, exactly ^^ Sep 6, 2019 at 4:37
• You might want to include the mathematical terms: rot13(qvtvgny ebbg & zbqhyb 9), which aren't equivalent methods but do give equivalent results for this puzzle.
– amI
Sep 6, 2019 at 5:33
• Nice, I didn't notice that there has a math property here:P, Good job! Sep 6, 2019 at 7:20

To be precise, my answer is also in the same lines as that of

supersonic, but with a generalization at sum of the digits of the given number level. It is of the form ( (9*n) +1)- for Finale numbers and we cannot do so for their counterparts