The first term of the formula used to calculate PV is PV * (1+rate) ^ nper
(as in your link). Using your first example this gives 4.84861419016704E+304
so close enough to Excel’s limit (of 9.99999999999999E+307
) that no element of the first term would have to increase by much for the result to exceed the inbuilt limitation, for which your second example seems to have been enough.
Note that, as @Juliusz has pointed out, the first parameter is the interest rate per period and 19
represents 1900%
. For 240 periods (looks like 20 years) the combination is not realistic (ie 1900% per month). Also, the rate should not normally be negative (better to handle whether in or out by signing the payment amount).