I'm using a Dell 3147 laptop with Intel Pentium N3530 CPU and an LG 25UM58 Ultrawide monitor connected by an HDMI cable
Just updating the graphics drivers, max resolution available is 1920 X 1080
I tried custom resolution utility, Intel HD graphics control Panel, Intel Graphics command center to install a custom resolution but nothing worked
You should make sure your BIOS and Graphics drivers are both up to date. Latest BIOS is available is A12 (here: https://www.dell.com/support/home/us/en/04/product-support/product/inspiron-11-3147-laptop/drivers)
Dell offers graphics driver version 10.18.10.4242 on their download page (here: https://www.dell.com/support/home/us/en/04/product-support/product/inspiron-11-3147-laptop/drivers) but I see Intel generic version 126.96.36.19900 (here: https://downloadcenter.intel.com/download/29311/Intel-Graphics-Driver-for-Windows-15-33-?product=855...) also supports this processor.
Hope this helps,