Table of 28

Introduction

The number 28 (or twenty-eight) is a natural number that comes after 27 and before 29. It is a composite number, with 1, 2, 4, 7, and 14 as its proper divisors.

The second perfect number is twenty-eight, which is equal to the sum of its proper divisors: \begin{equation}

1+2+4+7+14=28

\end{equation}.

Being a perfect number,

\begin{equation}

23-1 \text { times }(23-1)=28

\end{equation}relates it to the Mersenne prime 7, which is also a perfect number. 496 is the previous perfect number after 6.

Table of Content

1. Some definitions in maths

2. Factors of 28

3. Table of 28 in Words

4. Solved Examples

5. Table of 28

6. Frequently Asked Questions – FAQs

Some Definitions in Maths

1. The sum of the totient functions for the first nine integers is twenty-eight.

2. Due to the fact that 157, or more than 28 twice, is the largest prime factor of 28 number, \begin{equation}

3. 28^2+1=785

\end{equation} 28 is a Stermer number.

4. With the terms 12, 16, and 21 coming before it, it appears in the Padovan sequence (it is the sum of the first two of these).

5. Because it appears repeatedly in a Fibonacci-like sequence starting with its decimal digits—2, 8, 10, 18, 28—it is also a Keith number.

6. Having a prime factorization of the form, twenty-eight is the third positive integer \begin{equation}

2^2 q

\end{equation} where q is an odd number.

7. Only the positive integer twenty-eight has a distinct Kayles nim-value.

Factors of 28

The numbers that can divide 28 in two equally, or factors, are 28. 1, 2, 4, 7, 14, and 28 make up this list. The remainder will equal 0 when we divide 28 by any of its factors, and the quotient will be a natural number.

To determine the pair factors, multiply the two numbers in a pair to obtain the original number, 28, which are the following numbers.

Solved Examples

Q1. Add the natural numbers from 1 to 3 to get the multiples of 28?

Ans:

\begin{array}{ll}

27 \times 1=27 & 27+1, \text { is } 28 \\

27 \times 2=54 & 54+2 \text { is } 56 \\

27 \times 3=81 & 81+3 \text { is } 84

\end{array}

Q2. Ram makes 7 cream rolls every day. How many cream rolls does he make in 28 days?

Ans: \begin{equation}

7 \times 28=196

\end{equation}

Q3. Sam earns $50 per hour. How much money will she earn if she works for 28 hours?

Ans: \begin{equation}

50 \times 28=\$ 1400

\end{equation}

Q5.What is the LCM of 28?

Ans:\begin{equation}

2^2 \times 7^1

\end{equation}

Table of 28

Table of 28 in Words

1. Twenty-Eight times one equals to Twenty-Eight

2. Twenty-Eight times two equals to Fifty-Six

3. Twenty-Eight times three equals to Eighty-Four

4. Twenty-Eight times four equals to One Hundred And Twelve

5. Twenty-Eight times five equals to One Hundred And Forty

6. Twenty-Eight times six equals to One Hundred And Sixty-Eight

7. Twenty-Eight times seven equals to One Hundred And Ninety-Six

8. Twenty-Eight times Eight equals to Two Hundred And Twenty-Four

9. Twenty-Eight times Nine equals to Two Hundred And Fifty-Two

Twenty-Eight times Ten equals to Two Hundred And Eighty