RSA Decrypt using Private Key in PEM File

I have short strings that I receive from another Web app that are encrypted with RSA-2048. The keypairs were generated on a CentOS server like this:

ssh-keygen -t rsa -f thekey -N '' -b 2048
cat thekey > ../priv.pem
ssh-keygen -f thekey.pub -e -m pem > ../pub.pem

Can your RSA library use this private key to decrypt strings encrypted using the public key above?

As an example, I encrypted the string "20052829374" using the public key and base64 encoded it (attached) and need to be able to decrypt it using the attached private key from C#.

If you have a code sample, it would be great.