In order to check Artifactory version number of your organization's Artifactory SaaS account, please use following steps.
- Login to your Artifactory SaaS account as a user who as Artifactory Admin permission
- Modify URL by appending /api/system to your Artifactory SaaS base URL. For example, https://support.artifactoryonline.com/support/api/system
- Access the URL
- Search for artifactory.version
Also, you can get the same result by using REST API.