Getting Object Numbers From Active Directory

Users:
(Get-ADUser -Filter *).Count

Computers:
(Get-ADComputer -Filter *).Count

Groups:
(Get-ADGroup -Filter *).Count

Enabled or disabled users:
(Get-AdUser -filter 'Enabled -eq $true').count
(Get-AdUser -filter 'Enabled -eq $false').count

Group users:
(Get-ADGroup GS-VPN-Users -Properties *).Member.Count

OU users:
(Get-ADUser -Filter * -SearchBase "OU=Users, OU=PNL,DC=pnl,DC=com").Count