28concepts is a full service, in-house digital marketing and design creative services group with over a decade of experience in the creative industry. We develop integrated marketing solutions that drive business and boost revenue. We don’t need to outsource your work overseas or to robots. We are real people, with a real passion for what we do – see for yourself.
And we really like the number 28…
The number 28 is kinda magical. It is, in fact, a perfect number.
- It is a composite number, its proper divisors being 1, 2, 4, 7, and 14.
- As a perfect number, it is related to the Mersenne prime 7, since 22(23 – 1) = 28. The next perfect number is 496, the previous being 6.
- Twenty-eight is the third Granville number. The next Granville number is 96, the previous being 24.
- Twenty-eight is the sum of the totient function for the first nine integers.
- Twenty-eight is not the aliquot sum of any number other than itself and is therefore not a component in an aliquot sequence.
- Since the greatest prime factor of 282 + 1 = 785 is 157, which is more than 28 twice, 28 is a Størmer number.
- Twenty-eight is a harmonic divisor number, a happy number, a triangular number, a hexagonal number, and a centered nonagonal number.
- It appears in the Padovan sequence, preceded by the terms 12, 16, 21 (it is the sum of the first two of these).
- It is also a Keith number, because it recurs in a Fibonacci-like sequence started from its base 10 digits: 2, 8, 10, 18, 28…
- Twenty-eight is the third positive integer with a prime factorization of the form
where q is an odd prime.
- Twenty-eight is the ninth and last number in early Indian magic square of order 3.
- There are twenty-eight convex uniform honeycombs.
- Twenty-eight is the only positive integer that has a unique Kayles nim-value.