REVERSAL-ADDITION PALINDROME TEST ON 1007377

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 1007377:
1007377
+ 7737001
step 1: 8744378
+ 8734478
step 2: 17478856
+ 65887471
step 3: 83366327
+ 72366338
step 4: 155732665
+ 566237551
step 5: 721970216
+ 612079127
step 6: 1334049343
+ 3439404331
step 7: 4773453674
+ 4763543774
step 8: 9536997448
+ 8447996359
step 9: 17984993807
+ 70839948971
step 10: 88824942778
+ 87724942888
step 11: 176549885666
+ 666588945671
step 12: 843138831337
+ 733138831348
step 13: 1576277662685
+ 5862667726751
step 14: 7438945389436
+ 6349835498347
step 15: 13788780887783
+ 38778808788731
step 16: 52567589676514
+ 41567698576525
step 17: 94135288253039
+ 93035288253149
step 18: 187170576506188
+ 881605675071781
step 19: 1068776251577969
+ 9697751526778601
step 20: 10766527778356570
+ 07565387772566701
step 21: 18331915550923271
+ 17232905551913381
step 22: 35564821102836652
+ 25663820112846553
step 23: 61228641215683205
+ 50238651214682216
step 24: 111467292430365421
+ 124563034292764111
step 25: 236030326723129532
+ 235921327623030632
step 26: 471951654346160164
+ 461061643456159174
step 27: 933013297802319338
+ 833913208792310339
step 28: 1766926506594629677
+ 7769264956056296671
step 29: 9536191462650926348
+ 8436290562641916359
step 30: 17972482025292842707
+ 70724829252028427971
step 31: 88697311277321270678
+ 87607212377211379688
step 32: 176304523654532650366
+ 663056235456325403671
step 33: 839360759110858054037
+ 730450858011957063938
step 34: 1569811617122815117975
+ 5797115182217161189651
step 35: 7366926799339976307626
+ 6267036799339976296637
step 36: 13633963598679952604263
+ 36240625997689536933631
step 37: 49874589596369489537894
+ 49873598496369598547894
step 38: 99748188092739088085788
+ 88758088093729088184799
step 39: 188506276186468176270587
+ 785072671864681672605881
step 40: 973578948051149848876468
+ 864678848941150849875379
step 41: 1838257796992300698751847
+ 7481578960032996977528381
step 42: 9319836757025297676280228
+ 8220826767925207576389139
step 43: 17540663524950505252669367
+ 76396625250505942536604571
step 44: 93937288775456447789273938
+ 83937298774465457788273939
step 45: 177874587549921905577547877
+ 778745775509129945785478771
step 46: 956620363059051851363026648
+ 846620363158150950363026659
step 47: 1803240726217202801726053307
+ 7033506271082027126270423081
step 48: 8836746997299229927996476388
1007377 takes 48 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 1,749,819 times since Saturday, March 9th, 2002.)