Check if N is a Balanced Prime number or not | Utility function to check if a number is prime or not ; Corner cases ; This is checked so that we can skip middle five numbers in below loop ; Function that returns true if n is a Balanced prime ; If n is not a prime number or n is the first prime then return false ; Initialize previous_prime to n - 1 and next_prime to n + 1 ; Find next prime number ; Find previous prime number ; Arithmetic mean ; If n is a weak prime ; Driver code
function isPrime ( n ) { if ( n <= 1 ) return false ; if ( n <= 3 ) return true ; if ( n % 2 == 0 n % 3 == 0 ) return false ; for ( let i = 5 ; i * i <= n ; i = i + 6 ) if ( n % i == 0 || n % ( i + 2 ) == 0 ) return false ; return true ; } function isBalancedPrime ( n ) { if ( ! isPrime ( n ) n == 2 ) return false ; let previous_prime = n - 1 ; let next_prime = n + 1 ; while ( ! isPrime ( next_prime ) ) next_prime ++ ; while ( ! isPrime ( previous_prime ) ) previous_prime -- ; let mean = ( previous_prime + next_prime ) / 2 ; if ( n == mean ) return true ; else return false ; } let n = 53 ; if ( isBalancedPrime ( n ) ) document . write ( " " ) ; else document . write ( " " ) ;