Quaternion.ToAngleAxis

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

Description

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

using UnityEngine;

public class Example : MonoBehaviour
{
    void Start()
    {
        // Extracts the angle - axis rotation from the transform rotation

        float angle = 0.0f;
        Vector3 axis = Vector3.zero;
        transform.rotation.ToAngleAxis(out angle, out axis);
    }
}