G = V / (t2 * M)
So we have:
M / V = 1 / (G * t2) = ρ = Universe's density
In physical cosmology, the age of the universe is the time elapsed since the Big Bang.
The best measurement of the age of the universe is 13.798±0.037 billion years
(13.798±0.037×109 years or 4.354±0.012×1017 seconds)within the Lambda-CDM concordance model.
Planck Collaboration (2015). “Planck 2015 results. XIII. Cosmological parameters”
The age of the Universe can be estimated by means of other methods too.
There are at least 3 ways:
(Nicolas Dauphas Nature 435, 1203-1205 (30 June 2005))
(Shinya Wanajo Astrophys.J. 577 (2002) 853-865)
( Harvey B. Richer: Astrophys.J.574:L155-L158,2002)
Replacing known values:
ρ = 1 / (G * t2) = 1 / ( (6.67408*10-11) * ( 4.354 * 1017)2 )
ρ = 1 / ( (6.67408*10-11) * (18.957316*1034) )
ρ = 1 / (126.52264356928 * 1023)  =  0.0079 * 10-23  Kg/m3 = 7.9 * 10-26 Kg/m3
ρ = 7.9 * 10-29 g/cm3
It is important to note that the achieved ρ is the total mass_energy density of the Universe. In other words, it is the sum of a number of different components including both normal (baryonic) and dark matter as well as the dark energy .