Twentyeight
Twentyeight is the written name of the integer 28. It is an even, composite number whose prime factorization is 2^2 × 7. The divisors of 28 are 1, 2, 4, 7, 14, and 28; the sum of the proper divisors is 28, making it a perfect number. It is also the fourth triangular number, since 1 + 2 + 3 + 4 + 5 + 6 + 7 equals 28. In number theory, 28 can be expressed as 2^(p−1)·(2^p−1) when 2^p−1 is a Mersenne prime; with p = 3 this yields 28.
In science, 28 is the atomic number of nickel (Ni), a transition metal known for its strength
In culture and everyday use, February commonly has 28 days in common years, while some months and
As a numeric unit, 28 has significance in various systems and is notable among small integers for