Break up IMSI into MCC, MNC, MSIN. Determine subscriber country and network.
const imsi = require('imsi-grok');
console.log(imsi.grok('247011234567890'));
Output:
{ mcc: '247',
mnc: '01',
country_iso: 'LV',
country_name: 'Latvia',
country_code: '371',
network_name: 'Latvian Mobile Phone',
msin: '1234567890' }