 75 number - In other fields: Encyclopedia II - 75 number - In mathematicsAs the sum of the first five pentagonal numbers, seventy-five is a pentagonal pyramidal number. It is also an enneagonal number.
It is also a Keith number, because it recurs in a Fibonacci-like sequence started from its base 10 digits: 7, 5, 12, 17, 29, 46, 75... But there is no integer that added up to its own digits adds up to 75, hence 75 is a self number.
There are 75 uniform polyhedra.
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See also:75 number, 75 number - In mathematics, 75 number - In science, 75 number - In other fields Read more here: » 75 number: Encyclopedia II - 75 number - In mathematics |
