Numbers 81,000,000s

A page of the Numeropedia - the Special Encyclopedia of Numbers

80,000,000 81,000,00082,000,00083,000,000 – 84,000,000

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

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

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

81,198,121

[Math.]  90112 = 8119,8121 consisting of 2 consecutive odd numbers.

 

81,265,112

[Math.]  A pair of amicable numbers (75226888, 81265112).

 

81,274,365

[Math.] (References [1])

Pan-digital number

2× a zero-less

pan-digital number

Uses each of

9 digits 1-9 once

1,037,246,958

= 2×518,623,479

= 9×57,624,831

1,046,389,752

= 2×523,194,876

= 9×58,132,764

1,286,375,904

= 2×643,187,952

= 9×71,465,328

1,307,624,958

= 2×653,812,479

= 9×72,645,831

1,370,258,694

= 2×685,129,347

= 9×76,125,483

1,462,938,570

= 2×731,469,285

= 9×81,274,365

    

81,324,324

[Math.]  90182 = 81,324,324.

 

81,450,625

[Math.]  81,450,625 = (+81+450625)4 = 954.

 

81,812,025

[Math.]  Sum of the first 134 cube numbers:

13+23+…+1333+1343 = 81,812,025 = (1+2+…+133+134)2 = 90452.

 

xy,abc,def

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

 

For any xy = 10 to 99, there are always twelve 6-digit numbers abc,edf such that the sum (xy+abc,def) is equal to one of 12 digit-rotations of 076,923 or 153,846 and the number xy,abc,def is a multiple of 76,923.