The ornamental design for an airpurifier with humidifier, as shown and described.
1. Air purifier with humidifier
1.1 is a perspective view of an air purifier with humidifier showing our new design;
1.2 is a front elevation view thereof;
1.3 is a rear elevation view thereof;
1.4 is a left-side elevation view thereof;
1.5 is a right-side elevation view thereof;
1.6 is a top plan view thereof; and
1.7 is a bottom plan view thereof.
The broken line showing of portions of the air purifier with humidifier is for the purpose of illustrating unclaimed portions of the air purifier with humidifier and forms no part of the claimed design.