wikipedia tells me it might be an expensive-to-call number form the UK: "Any telephone number starting 09xx is charged at premium rates, in a similar fashion to a 900 number in North America. Previously the main virtual prefixes for premium rate phone calls were 0898 and 0891 along with some others (such as 0331, 0660, 0897). In the 1980s, when premium rate was introduced, the main prefixes were 0055, 0066 and 0077. Premium rate services in the UK can range from £0.10/min up to £1.50/min. Drop charge rates are also available which can cost the caller £0.10/call up to £1.50/call."
I'm curious.