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80

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This article is under construction.            

Please do not rely on any information it contains.            


80 is an integer, the smallest number where and are both products of 4 or more primes.

Membership in core sequences

Even numbers ..., 74, 76, 78, 80, 82, 84, 86, ... A005803
Composite numbers ..., 76, 77, 78, 80, 81, 82, 84, ... A002808
Abundant numbers ..., 70, 72, 78, 80, 84, 88, 90, ... A005101
Numbers that are the sum of two squares ..., 72, 73, 74, 80, 81, 82, 85, ... A001481

Sequences pertaining to 80

Divisors of 80 1, 2, 4, 5, 8, 10, 16, 20, 40, 80 A018275
Multiples of 80 80, 160, 240, 320, 400, 480, 560, 640, 720, 800, 880, 960, 1040, ...
sequence beginning at 15 ..., 53, 160, 80, 40, 20, 10, 5, 16, 8, 4, 2, 1, 4, 2, 1, 4, 2, 1, 4, 2, 1, ... A033480

Partitions of 80

There are 15796476 partitions of 80.

The Goldbach representations of 80 are: 7 + 73 = 13 + 67 = 19 + 61 = 37 + 43.

Roots and powers of 80

In the table below, irrational numbers are given truncated to eight decimal places.

TABLE GOES HERE

Logarithms and eightieth powers

In the OEIS specifically and mathematics in general, refers to the natural logarithm of , whereas all other bases are specified with a subscript.

As above, irrational numbers in the following table are truncated to eight decimal places.

TABLE GOES HERE

Values for number theoretic functions with 80 as an argument

0
−4
22
186
10
40
5
2
4 This is the Carmichael lambda function.
−1 This is the Liouville lambda function.

Factorization of some small integers in a quadratic integer ring with discriminant −80, 80

Since 80 is not squarefree, the of the [FINISH WRITING]

Factorization of 80 in some quadratic integer rings

In , 80 has the prime factorization of 2 4 × 5. But it has different factorizations in some quadratic integer rings.

TABLE GOES HERE

Representation of 80 in various bases

Base 2 3 4 5 6 7 8 9 10 11 12 13 80 15 16 17 18 19 20
Representation 1010000 2222 1100 310 212 143 120 88 80 73 68 62 5A 55 50 4C 48 44 40

See also

Some integers
0 1 2 3 4 5 6 7 8 9
10 11 12 13 14 15 16 17 18 19
20 21 22 23 24 25 26 27 28 29
30 31 32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47 48 49
1729