public static Rational multiplyByLong(Rational rational, long factor) throws IllegalDenominatorException, TimesOverflowException {
		try {
			if (ExtMath.areMultipliable(rational.getNumerator(), factor))
				return new Rational(rational.getNumerator() * factor, rational.getDenominator());
			else {
				if (!Rational.hasSameValueAs(rational, simplify(rational))) {
					if (multiplyByLong(simplify(rational), factor) == null) return null;
					return multiplyByLong(simplify(rational), factor);
				}
				return multiplyByLong(simplify(new Rational(factor, rational.getDenominator())), rational.getNumerator());
			}
		} catch (TimesOverflowException e) {
			e.printStackTrace();
			return null;
		}
	}