RSA keyblob size

[skylab]

Hi, this is my first post on this forum and I'm sorry if it isn't the right place to explain my problem.
I use CryptoAPI to encrypt data and the Algorithm is RSA. I need to save on disk the key pub/priv pair and this
work fine. The size of keyblob is 596 byte and I need to know why:
In the post at this address http://bytes.com/topic/c-sharp/answe...phertext-twice I read this code:

...
unsigned char *modulus = new unsigned char[128];
unsigned char *prime1 = new unsigned char[64];
unsigned char *prime2 = new unsigned char[64];
unsigned char *exponent1 =new unsigned char[64];
unsigned char *exponent2 = new unsigned char[64];
unsigned char *coefficient = new unsigned char[64];
unsigned char *privateExponent = new unsigned char[128];
...

The RSA theory says that i need: modulus (128 byte), prime1 (64 byte), prime2 (64 byte), publicExponent (or coefficient)(64 byte) and privateExponent (128 byte).
I don't understand the 2 variables: exponent1 and exponent2.

The sum of the 7 variables is 576 byte and I read in documentation that the blob header is 20 byte long. So 576 + 20 = 596 Byte long as I have in the keyblob on my disk.

Can someone explain me what are exponent1 and exponent2 and how I use it?

I'm sorry for my bad english.