Quaternion.ToAngleAxis

public void ToAngleAxis (out float angle, out Vector3 axis);

Description

Converts a rotation to angle-axis representation (angles in degrees).

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public float angle = 0.0F;
    public Vector3 axis = Vector3.zero;
    void Example() {
        transform.rotation.ToAngleAxis(out angle, out axis);
    }
}