Number with maximum number of prime factors | Return smallest number having maximum prime factors . ; Sieve of eratosthenes method to count number of prime factors . ; Finding number having maximum number of prime factor . ; Driver program
function maxPrimefactorNum ( N ) { var arr = Array . from ( { length : N + 5 } , ( _ , i ) => 0 ) ; for ( i = 2 ; i * i <= N ; i ++ ) { if ( arr [ i ] == 0 ) { for ( j = 2 * i ; j <= N ; j += i ) { arr [ j ] ++ ; } } arr [ i ] = 1 ; } var maxval = 0 , maxvar = 1 ; for ( i = 1 ; i <= N ; i ++ ) { if ( arr [ i ] > maxval ) { maxval = arr [ i ] ; maxvar = i ; } } return maxvar ; } var N = 40 ; document . write ( maxPrimefactorNum ( N ) ) ;