For more information on Long, see Primitive Data Types.
The following are methods for Long.
public String format()
Type: String
Long myLong = 4271990; system.assertEquals('4,271,990', myLong.format());
public Integer intValue()
Type: Integer
Long myLong = 7191991; Integer value = myLong.intValue(); system.assertEquals(7191991, myLong.intValue());
public static Long valueOf(String stringToLong)
Type: Long
Long L1 = long.valueOf('123456789');