see googles new calculator will calc factorials over 3000

[Thomas Okken]

N! going up to "over 3000" sounds like the calculator uses a decimal floating-point format with a four-digit exponent. (Free42 Decimal 1.4.x used a format with those properties, and could handle up to 3248!)

N! going up to 19515 sounds like the calculator uses a binary floating-point format with an exponent going up to 249,999. Having an exponent that represents a power of two but whose maximum value looks very decimal is pretty weird, but that's all I can make of it. :-)