Numbers 81,000,000s

A page of the Numeropedia - the Special Encyclopedia of Numbers

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]

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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.