I agree with @chirlu and @reosarevok that the ISWC Work number is just a unique number, given to a composition ("work") that has been legally registered by the composer at his/her national organization. It does not contain any meta data like IPI numbers, at least not in my country (Netherlands). Though: if you know that unique number, the national organization of the composer, can find the title of the work and its composer. And I assume, that in near future, you can look up the number in an international database and find the work title and composer Maybe there even is already such a database? Perhaps another member knows?
Oh and perhaps interesting for you to know, in my country the work number has not the prefix T but the prefix W and, after the 9-digits work identifier number no numeric check number follows, in my country.
And yes @smokeonthewater with the ISRC Recording number it is different: it has meta data: the first 2 characters represent the country (for example US) then the next 3 characters represent the unique code of the producer given to the producer by his/her national organization (for example R3G) and the following 2 digits must represent the year of the production (for example 16 means 2016) and then the last 5 digits represent in order of production the number of the track that was produced, so in this example e.g.
And, in some notations, the - is left out, so: USR3G1600024