Is mutating two distinct part of an object in an unsynchronized way unsafe?

Question

Lets say I have a relatively simple object with two properties :

@Data
public class MyObject {
    public Integer a;
    public Integer b;
}

can I safely mutate a in some thread and b in some other thread safely ? for example, would this code be safe from race conditions ?

public MyObject compute() {
    MyObject newObj = new MyObject();
    List<Runnable> tasks = new ArrayList<>();
    Runnable computeATask = () -> {
        Integer a = computeA();
        newObj.setA(a);
    };
    Runnable computeBTask = () -> {
        Integer b = computeB();
        newObj.setB(b);
    };
    tasks.add(computeATask);
    tasks.add(computeBTask);
    tasks.stream().parallel().forEach(Runnable::run);
    return newObj;
}