error detecting rfid tags

first i checked the serial input of aurdino thts y i wrote this program

#include <LiquidCrystal.h>

String  incoming = 0;  
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() 
{
  lcd.begin(16, 2);
  lcd.print("ARMCET");
  Serial.begin(9600);   
}

void loop() 
{
  lcd.setCursor(0, 1);
  if (Serial . available() > 0) {
                incoming =  Serial.read();
                lcd.println( incoming  );
                Serial.print(incoming ); 
                
              
}
}

in this when i declared as char it shows the card no as 16703301 but when i change the decleration as string it shows card no as 49545548515148491310

in the below prg i declered as string only #include <LiquidCrystal.h>

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

String readString;

void setup() {
	Serial.begin(9600);
         lcd.begin(16, 2);
        }

void loop() {

        //expect a string like wer,qwe rty,123 456,hyre kjhg,
        //or like hello world,who are you?,bye!,
        lcd.setCursor(0, 1);
        while (Serial.available()) {
        delay(10);  //small delay to allow input buffer to fill
    
        char c = Serial.read();  //gets one byte from serial buffer
        if (c == ',') {break;}  //breaks out of capture loop to print readstring
        readString += c; } //makes the string readString  
            
      if (readString.length() >0) {
      Serial.println(readString); //prints string to serial port out
      
       if(readString =="16703301<CR><LF>")// here i changed to "49545548515148491310" but when card shown it is not executing this loop
       {
          Serial.print("hello");
          lcd.print("hello");
        }
        
        else if(readString == 16705890)
       {
          Serial.print("HI");
          lcd.print("hi");
        }
        else
        {
          Serial.print("enterno");
          lcd.print("enter no");
        }
        readString=""; //clears variable for new input
   }
}