# Find Prime number in C++

## Prime number program in C++

A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. It means a prime number is only divisible by 1 and itself, and it start from 2. The smallest prime number is 2.

## Prime number program in C++

```#include<iostream.h>
#include<conio.h>

void main()
{
int i,no;
clrscr();
cout<<"Enter any num: ";
cin>>no;
if(no==1)
{
cout<<"Smallest prime num is 2";
}
for(i=2;i<no;i++)
{
if(no%i==0)
{
cout<<"Not prime num";
break;
}
}
if(no==i)
{
cout<<"Prime num";
}
getch();
}
```

## Output

```Enter any num: 10
Not Prime Num
```

## Print next Prime number

When we enter any number this code will print next Prime number.
Example: Suppose we enter 5 then next prime number is 7.

## Prime number program in C++

```#include<iostream.h>
#include<conio.h>

void main()
{
int i,j=2,num;
clrscr();
cout<<"Enter any num: ";
cin>>num;
cout<<"Next prime num: ";
for(i=num+1;i<3000;i++)
{
for(j=2;j<i;j++)
{
if(i %j==0)
{
break;
} // if
} // for
if(i==j || i==1)
{
cout<<"\t"<<i;
break;
} // if
}  // outer for
getch();
}
```

## Output

```Enter any num: 10
Next prime num 11
```