Can 人口 be interpreted as a number?

Question

I was just in my iTalki class, and it seems I've been making an error for years whereby I refer to 人口 as 大/小 instead of 多/少 (which came up in this question, so it's seems I'm not the only one making this error). I think my error arose because I think of 人口 as a number, so I might think of something like the following (the numbers are approximate for simplicity):

北京的人口是两千万。 苏州的人口是一千万。因为两千万大于一千万，所以北京的人口大于苏州的人口。 [✗]
Beijing's population is 20 million. Suzhou's population is 10 million. 20 million is more than 10 million, so Beijing's population is greater than Suzhou's population.

Okay, I now know to use 多/少 to compare 人口, so the second 大于 above should be 多于. But I feel like people say things like 北京的人口是两千万 with or without adding a 人 (or 个人), e.g.:

北京的人口是21893095人 [source]
北京的人口是1633万 [source]

And if 人口 is a number, then numbers are compared with 大/小 and not 多/少. Maybe there's sometimes a phantom 人 in these examples: it functions as if it's there, but it's omitted.

Question: Can 人口 be interpreted as a number?

Answer 1

You can see population (人口) as a 数字/数目 or a 数量

1000 is a 数字; 1000人 is a 数量

北京的人口(数量)是二千万人 (二千万人这个数量多于一千万人那个数量)

北京的人口(数目)是二千万 (二千万这个数目大于一千万那个数目)

人口数字高達二千萬 (population reaches the number of 20,000,000)

人口数量多達二千萬人 (population up to 20,000,000 people)

• the classifier 人 can be omitted in 人口数量 because it is strongly implied

• the classifier 人 is not grammatical to use in 人口數目 because we don't count 数字/数目 as how many but now big

My conclusion:

北京人口多于苏州 compare the number of people in those two places

北京的人口数目大于苏州的人口数目 compare the exact number of those two populations

Answer 2

北京有多少人口?

两千万.

苏州有多少人口?

一千万.

那個地方人口多? 多多少?

北京人口多於苏州, 多一千万人. (一千万人 is a quantity, not a pure number.)

那個地方人口總數較大? 為什麼?

北京人口總數大於苏州. 因為两千万大於一千万.