Product of unique prime factors of a number | A function to print all prime factors of a given number n ; Handle prime factor 2 explicitly so that can optimally handle other prime factors . ; n must be odd at this point . So we can skip one element ( Note i = i + 2 ) ; While i divides n , print i and divide n ; This condition is to handle the case when n is a prime number greater than 2 ; Driver Code
< ? php function productPrimeFactors ( $ n ) { $ product = 1 ; if ( $ n % 2 == 0 ) { $ product *= 2 ; while ( $ n % 2 == 0 ) $ n = $ n / 2 ; } for ( $ i = 3 ; $ i <= sqrt ( $ n ) ; $ i = $ i + 2 ) { if ( $ n % $ i == 0 ) { $ product = $ product * $ i ; while ( $ n % $ i == 0 ) $ n = $ n / $ i ; } } if ( $ n > 2 ) $ product = $ product * $ n ; return $ product ; } $ n = 44 ; echo productPrimeFactors ( $ n ) ; ? >