>>24513451
You could probably figure it out through inferences and comparisons.
The key point would be how Gulliver's penis does come up as a plot point in the Lilliputian section of the book when there is a fire and he puts it out by pissing on it.
Now when firefighting the firefighters typically use a hose which shoots a stream of water reaching a few inches to a foot in width depending on the pressure. Now obviously he is not pissing with the pressure force of a firehose so it would fair on the wider end lets say 1 Lilliputian foot in width.
Lilliputians are described as 1/12 the size of Gulliver so the "firehose stream" of 1 Lilliputian foot makes Gulliver's piss stream roughly 1 human inch at the time. The typical urination stream width of a human male is 0.2 inches meaning Gulliver was pissing a stream 5 times the normal width. Furthermore the average urethra size 0.6 inches and as we know larger holes produce wider streams lining up with a stream 5 times wider. Using the Freeman's ratio hose to stream ratio which isn't a 1 to 1 increase we conclude Gulliver has a urethra equivalently 3 times bigger at 1.8 inch diameter urethra. The urethra taking up about 10% of the penis shaft girth means that Gulliver's penis has a girth of almost 18 inches.
The ratio of a penis girth to length is not exact but when erect as he would be when getting his dick sucked it is about 1:1.12. So Gulliver is working with maybe a 20 incher. The surface area using the formula for an elongated dome gives 1,100 square inches.
As for the mouths of the women. They can't fit it into the mouth so instead of depth of mouth/throat we will have to use lip/open mouth area covering the dick. Normal human lips cover 33 square inches which would mean his dick could have 33 human women fit their mouths on it.
Recalling that Lilliputians are 1/12 the size of a human 396 Lilliputian women would be needed to give Gulliver a blowjob.