This is a very ordinary 2.2M Ohm resistor. Carbon film is chosen because it is inexpensive, though there is an additional benefit; The beige paint colour represents carbon film, and that makes the simple colour bands easier to read. Metal film types have a dark green or blue paint and additional colour bands. The 0.5 Watt power rating is chosen because that makes the resistor a bit larger than smaller power types, so it is easier to handle.
In the circuit, this resistor provides a very small current into the transistor base and "tickles" it into conduction, after which regeneration and reflex action continue to make the transistor act as an active diode with substantial current gain.
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