text: Number with maximum number of prime factors | Java program to find integer having maximum number of prime factor in first N natural numbers . ; 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
code: import java . util . Arrays ; public class GFG { static int maxPrimefactorNum ( int N ) { int arr [ ] = new int [ N + 5 ] ; Arrays . fill ( arr , 0 ) ; for ( int i = 2 ; i * i <= N ; i ++ ) { if ( arr [ i ] == 0 ) { for ( int j = 2 * i ; j <= N ; j += i ) { arr [ j ] ++ ; } } arr [ i ] = 1 ; } int maxval = 0 , maxint = 1 ; for ( int i = 1 ; i <= N ; i ++ ) { if ( arr [ i ] > maxval ) { maxval = arr [ i ] ; maxint = i ; } } return maxint ; } public static void main ( String [ ] args ) { int N = 40 ; System . out . println ( maxPrimefactorNum ( N ) ) ; } }