Collatz' Conjecture

BigInteger c = new BigInteger("165455345345345361652165161151651654698465165168435135168465132321556846846551");
System.out.println(c);
String c_ = c.toString();
final BigInteger TWO = new BigInteger("2");
final BigInteger THREE = new BigInteger("3");
for(; c.compareTo(BigInteger.ONE) == 1; c_ = c.toString(), System.out.println(c_)) {
    if(Integer.parseInt("" + c_.charAt(c_.length() - 1)) % 2 == 0) {
        c = c.divide(TWO);
    } else {
        c = c.multiply(THREE).add(BigInteger.ONE);
    }
}