| 
| REVERSAL-ADDITION
PALINDROME
TEST ON 
1064912 |  | 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 1064912: |  | | 1064912 + 2194601
 step 1: 3259513
 + 3159523
 step 2: 6419036
 + 6309146
 step 3: 12728182
 + 28182721
 step 4: 40910903
 + 30901904
 step 5: 71812807
 + 70821817
 step 6: 142634624
 + 426436241
 step 7: 569070865
 + 568070965
 step 8: 1137141830
 + 0381417311
 step 9: 1518559141
 + 1419558151
 step 10: 2938117292
 + 2927118392
 step 11: 5865235684
 + 4865325685
 step 12: 10730561369
 + 96316503701
 step 13: 107047065070
 + 070560740701
 step 14: 177607805771
 + 177508706771
 step 15: 355116512542
 + 245215611553
 step 16: 600332124095
 + 590421233006
 step 17: 1190753357101
 + 1017533570911
 step 18: 2208286928012
 + 2108296828022
 step 19: 4316583756034
 + 4306573856134
 step 20: 8623157612168
 + 8612167513268
 step 21: 17235325125436
 + 63452152353271
 step 22: 80687477478707
 + 70787477478608
 step 23: 151474954957315
 + 513759459474151
 step 24: 665234414431466
 + 664134414432566
 step 25: 1329368828864032
 + 2304688288639231
 step 26: 3634057117503263
 + 3623057117504363
 step 27: 7257114235007626
 + 6267005324117527
 step 28: 13524119559125153
 + 35152195591142531
 step 29: 48676315150267684
 + 48676205151367684
 step 30: 97352520301635368
 + 86353610302525379
 step 31: 183706130604160747
 + 747061406031607381
 step 32: 930767536635768128
 + 821867536635767039
 step 33: 1752635073271535167
 + 7615351723705362571
 step 34: 9367986796976897738
 + 8377986796976897639
 step 35: 17745973593953795377
 + 77359735939537954771
 step 36: 95105709533491750148
 + 84105719433590750159
 step 37: 179211428967082500307
 + 703005280769824112971
 step 38: 882216709736906613278
 + 872316609637907612288
 step 39: 1754533319374814225566
 + 6655224184739133354571
 step 40: 8409757504113947580137
 + 7310857493114057579048
 step 41: 15720614997228005159185
 + 58195150082279941602751
 step 42: 73915765079507946761936
 + 63916764970597056751937
 step 43: 137832530050105003513873
 + 378315300501050035238731
 step 44: 516147830551155038752604
 + 406257830551155038741615
 step 45: 922405661102310077494219
 + 912494770013201166504229
 step 46: 1834900431115511243998448
 + 8448993421155111340094381
 step 47: 10283893852270622584092829
 + 92829048522607225839838201
 step 48: 103112942374877848423931030
 + 030139324848778473249211301
 step 49: 133252267223656321673142331
 + 133241376123656322762252331
 step 50: 266493643347312644435394662
 + 266493534446213743346394662
 step 51: 532987177793526387781789324
 + 423987187783625397771789235
 step 52: 956974365577151785553578559
 + 955875355587151775563479659
 step 53: 1912849721164303561117058218
 + 8128507111653034611279482191
 step 54: 10041356832817338172396540409
 + 90404569327183371823865314001
 step 55: 100445926160000709996261854410
 + 014458162699907000061629544001
 step 56: 114904088859907710057891398411
 + 114893198750017709958880409411
 step 57: 229797287609925420016771807822
 + 228708177610024529906782797922
 step 58: 458505465219949949923554605744
 + 447506455329949949912564505854
 step 59: 906011920549899899836119111598
 + 895111911638998998945029110609
 step 60: 1801123832188898898781148222207
 + 7022228411878988988812383211081
 step 61: 8823352244067887887593531433288
 + 8823341353957887887604422533288
 step 62: 17646693598025775775197953966576
 + 67566935979157757752089539664671
 step 63: 85213629577183533527287493631247
 + 74213639478272533538177592631258
 step 64: 159427269055456067065465086262505
 + 505262680564560760654550962724951
 step 65: 664689949620016827720016048987456
 + 654789840610027728610026949986466
 step 66: 1319479790230044556330042998973922
 + 2293798992400336554400320979749131
 step 67: 3613278782630381110730363978723053
 + 3503278793630370111830362878723163
 step 68: 7116557576260751222560726857446216
 + 6126447586270652221570626757556117
 step 69: 13243005162531403444131353615002333
 + 33320051635313144430413526150034231
 step 70: 46563056797844547874544879765036564
 
 | 
 |  
 | 1064912 takes 70 iterations / steps to resolve into a 35 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.)
 
 
 
| Digits | Number | Result | 
|---|
 
| 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 Indeterminable times since Saturday, March 9th, 2002.)
 |