RSA keys are stored using an algorithm-name of ‘ssh-rsa’. (Keys stored like this are also used by the updated RSA signature schemes that use hashes other than SHA-1.)
The public key data has already provided the key modulus and the public encoding exponent. The private data stores:
mpint: the private decoding exponent of the key.
mpint: one prime factor p of the key.
mpint: the other prime factor q of the key. (RSA keys stored in this format are expected to have exactly two prime factors.)
mpint: the multiplicative inverse of q modulo p.