Need Help with RSA Decryption

nssn44

Hello,
I have a question regarding the RSA decryption, I have calculated the private key using public key and the modulus(ed mod (q-1)(p-1)=1), however this number is 5 digit long and I am unable to calculate the plain text.
I am trying to use the following formula to calculate the plain text:
M=((M^e)mod n)^d mod n.
where M is plain text, e is public key, d is private key, and n is modulus. I do have the encrypted message which contains 5 digit numbers.
What I am trying to do is to take the encrypted message to the power of private key and get its reminder when it is divided by modulus, which should be the plain text(represented by its ascii number)
for instance if the d=11227 and the encrypted letter 39822 and n is 105567
I need to calculate (39822^11227)mod 105567

Can anyone advise me what is the best method of calculating the plain text, I have tried to use some online scientific calculators, however they fail to provide me with a valid result, as the calculated number is too big for them to handle it.
Your help is truly appreciated
Many thanks