The whole idea of the RSA private key is the hardness of factorisation of two very large prime numbers. That’s why recommended RSA keys are >2048bit long. I won’t get into RSA details itself. If You need any info, it’s here: WIKI For a sake of demonstration, 256bit public_key will be used. With the current hardware that we have these days, it’s very easy crackable.
-----BEGIN PUBLIC KEY-----
-----END PUBLIC KEY-----
Lets convert it to a more ‘mathematical’ expression: