Numbers 81,000,000,000s

A page of the Numeropedia - the Special Encyclopedia of Numbers

80,000,000,00081,000,000,00082,000,000,000 – 83,000,000,00084,000,000,000

85,000,000,00086,000,000,00087,000,000,00088,000,000,00089,000,000,000

All Numbers  – [1B] –  [10B] –  [20B] – [30B] – [40B] – [50B] – [60B] – [70B] – [80B] – [90B] & [100B]

1  - 10 - 100  - 1000 - 10,000 - 100,000 - 1M - 10M - 100M1B10B - 100B - 1T - 10T - 100T - 1Q ...

81,017,083,225

[Math.]  Sum of the first 754 cube numbers:

13+…+7543 = 81,017,083,225 = (1+…+754)2 = 284,6352.

 

81,393,657,019

[Math.]  Alternating addition/subtraction of factorials: 81,393,657,019 =

14!–13!+12!–11!+10!–9!+8!–7!+6!–5!+4!–3!+2!–1!.

 

81,447,452,100

[Math.]  Sum of the first 755 cube numbers:

13+…+7553 = 81,447,452,100 = (1+…+755)2 = 285,3902.

 

81,787,109,375

[Math.]  Its odd powers end with 81,787,109,375.  Its even powers end with 18,212,890,625.

 

81,787,109,376

[Math.]  An automorphic number, whose powers end with the number itself. It is extracted from a 17-digit automorphic number 43,740,081,787,109,376, which remains automorphic when dropping the left-most digits.

 

81,879,533,316

[Math.]  Sum of the first 756 cube numbers:

13+…+7563 = 81,879,533,316 = (1+…+756)2 = 286,1462.


xy,zwv,abc,def

[Math.]  For any xy,zwv = 10,000 to 99,999, there are always six 6-digit numbers abc,edf such that xy,zwv +abc,def is equal to one of 6 digit-rotations of 142,857 and the number xy,zwv,abc,def is a multiple of 142,857.