Try like this
$VmInfo=ForEach ($Datacenterin (Get-Datacenter)) {
ForEach ($VMin ($Datacenter|Get-VM|where {$_.powerstate -match"on"} |get-vmguest)) {
$vm|Select @{N="VM_NAME#";E={$vm.Hostname}},
@{N="VM_CPU_Core#";E={$vm.NumCPU}},
@{N="VM_IP#";E={$vm.IPAddress}},
@{N="VM_OS";E={$vm.OSFullName}},
@{N="VM_DC";E={$Datacenter.name}},
@{N="VM_NOTES";E={$Vm.VM.Notes}}
}
}
$VmInfo|Export-Csv-NoTypeInformation-UseCulture-Path"d:\temp\report.csv"