Back to [Numbers 9900-9999]

 

9,990

[Math.]   (Sequence of  numbers (10n–10m, n > 2m).

99902 = 99,800,100 and 9980+0+10+0 = 9990.

 

9,991

[Math.]  (Sequence of numbers (10n–9), n³ 2)

99912 = 99,820,081 and 9982+0+0+8+1 = 9991. 

 

9,992…  

 

9,993...

 

9,994

[Math.] 

 94 = 47×2 and, reversely, 49 = 47+2

994 = 497×2 and, reversely, 499 = 497+2

9994 = 4997×2 and, reversely, 4999 = 4997+2

99994 = 49997×2 and, reversely, 49999 = 49997+2

999994 =  499997×2 and, reversely, 499999 = 499997+2

...

 

9,995

[Math.]  99952 = 99,900,025. (Sequence of numbers (10n–5), n³ 2).

 

9,996

[Math.]  99962 = 99,920,016. (Sequence of numbers (10n–4), n³ 2).

 

9,997

[Math.]  (Sequence of numbers (10n–3), n³ 2)

9,9973 = 999,100,269,973 = (9991+0+0+269+9+7+3)3.

 

9,998

[Math.]  (Sequence of  numbers (10n–2), n³ 2).

99983 = 999,400,119,992 = (9994–00+11–99+92)3 

 

9,999

[Math.]  Its odd powers end with 9999. Its even powers end with 0001.

99992 = 99,980,001 and 9998+0001 = 9999.

99993 = 999,700,029,999 and 9997+0002 = 9999.

 

[Math.] 

11113 = 1,371,330,631 and 13+7133+0631 = 7777.

22223 = 10,970,645,048 and 109+7064+5048 = 12221 and 1+2221 = 2222

33333 = 37,025,927,037 and 370+2592+7037 = 9999.

44443 = 87,765,160,384 and 877+6516+0384 = 7777.

55553 = 171,416,328,875 and 1714+1632+8875 = 12221 and 1+2221 = 2222

66663 = 296,207,416,296 and 2962+0741+6296 = 9999.

77773 = 470,366,406,433 and 4703+6640+6433 = 17776 and 1+7776 = 7777

88883 = 702,121,283,072 and 7021+2128+3072 = 12221 and 1+2221 = 2222

99993 = 999,700,029,999 and 9997+0002+9999 = 2×9999.

 

[Math.] 

11,111,1113 = 1371742071330590260631

 and 13+7174+2071+3305+9026+0631 = 22220

22,222,2223 = 10973936570644722085048

   and 109+7393+6570+6447+2208+5048 = 27775

33,333,3333 = 37037035925925937037037

   and 370+3703+5925+9259+3703+7037 = 3×9999

44,444,4443 = 87791492565157776680384

   and 877+9149+2565+1577+7668+0384 = 22220

55,555,5553 = 17146775 89163237 82578875

   and 1714+6775+8916+3237+8257+8875 = 37,774

66,666,6663 = 296296287407407496296296

   and 2962+9628+7407+4074+9629+6296 = 4×9999

77,777,7773 = 470507530466392459396433

   and 4705+0753+0466+3924+5939+6433 = 22220

88,888,8883 = 702331940521262213443072

   and 7023+3194+0521+2622+1344+3072 = 17776

99,999,9993 = 999999970000000299999999

   and 9999+9997+0000+0002+9999+9999 = 4×9999.

 

[Phone]  The number to key in text messaging on telephone keypad for letter Z.

 

[Trivia]  The largest 4-digit number or the maximum number that can be displayed by a 4-digit counter.

 

91-99 & 991-999 & 9991-9999 & 99991-99999…

[Math.]  Repeatedly inserting number 9 before ab and number 0 before cdin the square number abcd = (9x)2yields the square numbers: (99x)2 = 9ab0cd; (999x)2 = 99ab00cd…, for x = 1 to 9.

 

9,950-9,969 (separate page)

 

9,970-9,989 (separate page)    

 

9,990-9,999 (separate page).