REVERSAL-ADDITION PALINDROME TEST ON 1009150

Reverse and Add Process:

1. Pick a number.
2. Reverse its digits and add this value to the original number.
3. If this is not a palindrome, go back to step 2 and repeat.
Let's view this Reverse and Add sequence starting with 1009150:
1009150
+ 0519001
step 1: 1528151
+ 1518251
step 2: 3046402
+ 2046403
step 3: 5092805
+ 5082905
step 4: 10175710
+ 01757101
step 5: 11932811
+ 11823911
step 6: 23756722
+ 22765732
step 7: 46522454
+ 45422564
step 8: 91945018
+ 81054919
step 9: 172999937
+ 739999271
step 10: 912999208
+ 802999219
step 11: 1715998427
+ 7248995171
step 12: 8964993598
+ 8953994698
step 13: 17918988296
+ 69288981971
step 14: 87207970267
+ 76207970278
step 15: 163415940545
+ 545049514361
step 16: 708465454906
+ 609454564807
step 17: 1317920019713
+ 3179100297131
step 18: 4497020316844
+ 4486130207944
step 19: 8983150524788
+ 8874250513898
step 20: 17857401038686
+ 68683010475871
step 21: 86540411514557
+ 75541511404568
step 22: 162081922919125
+ 521919229180261
step 23: 684001152099386
+ 683990251100486
step 24: 1367991403199872
+ 2789913041997631
step 25: 4157904445197503
+ 3057915444097514
step 26: 7215819889295017
+ 7105929889185127
step 27: 14321749778480144
+ 44108487794712341
step 28: 58430237573192485
+ 58429137573203485
step 29: 116859375146395970
+ 079593641573958611
step 30: 196453016720354581
+ 185453027610354691
step 31: 381906044330709272
+ 272907033440609183
step 32: 654813077771318455
+ 554813177770318456
step 33: 1209626255541636911
+ 1196361455526269021
step 34: 2405987711067905932
+ 2395097601177895042
step 35: 4801085312245800974
+ 4790085422135801084
step 36: 9591170734381602058
+ 8502061834370711959
step 37: 18093232568752314017
+ 71041325786523239081
step 38: 89134558355275553098
+ 89035557255385543198
step 39: 178170115610661096296
+ 692690166016511071871
step 40: 870860281627172168167
+ 761861271726182068078
step 41: 1632721553353354236245
+ 5426324533533551272361
step 42: 7059046086886905508606
+ 6068055096886806409507
step 43: 13127101183773711918113
+ 31181911737738110172131
step 44: 44309012921511822090244
+ 44209022811512921090344
step 45: 88518035733024743180588
+ 88508134742033753081588
step 46: 177026170475058496262176
+ 671262694850574071620771
step 47: 848288865325632567882947
+ 749288765236523568882848
step 48: 1597577630562156136765795
+ 5975676316512650367757951
step 49: 7573253947074806504523746
+ 6473254056084707493523757
step 50: 14046508003159513998047503
+ 30574089931595130080564041
step 51: 44620597934754644078611544
+ 44511687044645743979502644
step 52: 89132284979400388058114188
+ 88141185088300497948223198
step 53: 177273470067700886006337386
+ 683733600688007760074372771
step 54: 861007070755708646080710157
+ 751017080646807557070700168
step 55: 1612024151402516203151410325
+ 5230141513026152041514202161
step 56: 6842165664428668244665612486
1009150 takes 56 iterations / steps to resolve into a 28 digit palindrome.

REVERSAL-ADDITION PALINDROME RECORDS

Most Delayed Palindromic Number for each digit length
(Only iteration counts for which no smaller records exist are considered. My program records only the smallest number that resolves for each distinct iteration count. For example, there are 18-digit numbers that resolve in 232 iterations, higher than the 228 iteration record shown for 18-digit numbers, but they were not recorded, as a smaller [17-digit] number already holds the record for 232 iterations.)

DigitsNumberResult
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
89
187
1,297
10,911
150,296
9,008,299
10,309,988
140,669,390
1,005,499,526
10,087,799,570
100,001,987,765
1,600,005,969,190
14,104,229,999,995
100,120,849,299,260
1,030,020,097,997,900
10,442,000,392,399,960
170,500,000,303,619,996
1,186,060,307,891,929,990
solves in 24 iterations.
solves in 23 iterations.
solves in 21 iterations.
solves in 55 iterations.
solves in 64 iterations.
solves in 96 iterations.
solves in 95 iterations.
solves in 98 iterations.
solves in 109 iterations.
solves in 149 iterations.
solves in 143 iterations.
solves in 188 iterations.
solves in 182 iterations.
solves in 201 iterations.
solves in 197 iterations.
solves in 236 iterations.
solves in 228 iterations.
solves in 261 iterations - World Record!
[View all records]

This reverse and add program was created by Jason Doucette.
Please visit my Palindromes and World Records page.
You have permission to use the data from this webpage (with due credit).
A link to my website is much appreciated. Thank you.

(This program has been run 1,767,550 times since Saturday, March 9th, 2002.)