- What are happy and unhappy numbers?
- What does amicable mean in a relationship?
- IS 496 a perfect number?
- Are 60 and 84 Amicable numbers?
- What is a proper divisor?
- What is the meaning of amicable?
- Why is 28 the perfect number?
- IS 220 a perfect number?
- How do I know if a number is amicable?
- What is the happiest number?
- How many amicable numbers are there?
- How many happy numbers are there?
- What is friendly numbers in math?
- What does 13 mean in math?
- Which of the following pairs of numbers is amicable *?

## What are happy and unhappy numbers?

The numbers for which the process of summing up of the squares of its digits ends in 1 are happy numbers.

…

On the other hand, numbers that don’t end in 1 are called unhappy or sad numbers..

## What does amicable mean in a relationship?

The adjective amicable means “friendly” — but in particular, use it when describing relations one might otherwise expect to be unfriendly. The end of a romantic relationship that’s less than amicable might involve broken dishes or broken bones.

## IS 496 a perfect number?

Also related to its being a perfect number, 496 is a harmonic divisor number, since the number of proper divisors of 496 divided by the sum of the reciprocals of its divisors, 1, 2, 4, 8, 16, 31, 62, 124, 248 and 496, (the harmonic mean), yields an integer, 5 in this case. … It is the largest happy number less than 500.

## Are 60 and 84 Amicable numbers?

Amicable Numbers The Greeks considered the pair of numbers 220 and 284 to be amicable or friendly numbers because the sum of the proper divisors of one of the numbers is the other number. a. 60 and 84 are amicable numbers.

## What is a proper divisor?

A positive proper divisor is a positive divisor of a number , excluding itself. For example, 1, 2, and 3 are positive proper divisors of 6, but 6 itself is not. The number of proper divisors of is therefore given by. where is the divisor function.

## What is the meaning of amicable?

Amicable, which derives from Late Latin amicabilis, meaning “friendly,” is one of a set of English words used to suggest cordial relationships. Amicable, neighborly, companionable, and friendly all mean marked by or exhibiting goodwill and an absence of antagonism.

## Why is 28 the perfect number?

A number is perfect if all of its factors, including 1 but excluding itself, perfectly add up to the number you began with. 6, for example, is perfect, because its factors — 3, 2, and 1 — all sum up to 6. 28 is perfect too: 14, 7, 4, 2, and 1 add up to 28.

## IS 220 a perfect number?

Perfect numbers have the property that the integer divisors sum to the number. … The factors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, and 110, which sum to 284.

## How do I know if a number is amicable?

…“amicable numbers”: two numbers are amicable if each is equal to the sum of the proper divisors of the other (for example, 220 and 284).

## What is the happiest number?

Defined the happiest number as the smallest number that finds the most other happy numbers with it, i.e. 7 found four other numbers (49, 97, 130, and 10) making it a rank 4 in happiness.

## How many amicable numbers are there?

Altogether there are 42 pairs of amicable numbers below 106.

## How many happy numbers are there?

For example, starting with 7 gives the sequence 7, 49, 97, 130, 10, 1, so 7 is a happy number. The first few happy numbers are 1, 7, 10, 13, 19, 23, 28, 31, 32, 44, 49, 68, 70, 79, 82, 86, 91, 94, 97, 100, … (OEIS A007770).

## What is friendly numbers in math?

An addition/subtraction strategy that uses a number that is easy to work from, typically 10 or a multiple of 10. For example, to solve 16 – 9, one might recognize that the friendly number 10 is 6 less than 16, then count down 1 more to 9 to find that the difference is 7. Compare helper facts.

## What does 13 mean in math?

In mathematics, the number 13 represents a quantity or value of 13. The whole number between 12 and 14 is 13. The number name of 13 is thirteen. 13 is 3 more than 10.

## Which of the following pairs of numbers is amicable *?

The smallest pair of amicable numbers is (220, 284). They are amicable because the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110, of which the sum is 284; and the proper divisors of 284 are 1, 2, 4, 71 and 142, of which the sum is 220.