Lagos is Nigeria economic capital while Abuja is the capital of Nigeria. Lagos transformed into a megacity and comprises of infrastructural facility Nigeria and Africa boast of.

Lagos is situated in the southwestern Nigeria and a land mass of about 3,577 square kilometers, despite this small land mass it remains the most populous state in Nigeria with population of about 18 million.
As 2014 Lagos state GDP was US$91 billion making it Africa 7th largest economy if it were a country and in 2016 it GDP was US$145.141 billion according to Lagos bureau of statistics. In 2018 the stood at US$136 billion with expectation of 4 percent growth in 2019 according to IMF.

Lagos take nominal GDP stands at US$33.679 billion as at 2018 making it richer than 39 Africa countries making it the 16th largest economy in Africa.

Here some of the countries that Lagos is more than.

Country Nominal GDP(US$ billion)
1 Uganda 33.569
2 Sudan 31.468
3 Senegal 25.32
4 Zambia 24.615
5 Zimbabwe 22.29
6 Botswana 19.651
7 Mali 17.833
8 Gabon 16.709
9 Mozambique 15.372
10 Burkina Faso 14.882
11 Mauritius 14.812
12 Namibia 13.961
13 Madagascar 12.734
14 Guinea 12.623
15 Equatorial Guinea 12.432
16 Chad 11.372
17 Benin 11.184
18 Republic of Congo 11.162
19 Rwanda 10.211
20 Niger 9.724
21 Somalia 7.903
22 Eritrea 7.718
23 Malawi 7.436
24 Togo 5.592
25 Mauritania 5.569
26 Eswatini 4.662
27 Sierra Leone 3.998
28 Burundi 3.573
29 Liberia 3.221
30 South Sudan 3.151
31 Lesotho 2.811
32 Djibouti 2.392
33 Central African Republic 2.285
34 Cabo Verde 2.042
35 The Gambia 1.741
36 Seychelles 1.654
37 Guinea-Bissau 1.538
38 Comoros 0.726
39 São Tomé and Príncipe 0.477

source and more:
http://www.sanwomi.com.ng/2020/01/up-lagos-check-out-39-africa-countries.html

cc: lalasticlala

If not that Lagos is part of Nigeria, it can exist as a successful nation on its own. Eko o ni baje

Wait for it...

Pauldollars:
If not that Lagos is part of Nigeria, it can exist as a successful nation on its own. Eko o ni baje

Anywhere can exist on its own.

As long as you are prepared to lose certain advantages.