Nile cruises suit solo travelers well, largely because the daily guided excursions naturally put you alongside other travelers, and shared meals and deck time create easy, low-pressure chances to talk to people without having to engineer it yourself.
Single-cabin pricing
Pricing varies by ship — some offer a dedicated single-cabin rate, while others apply a single supplement to a standard double cabin. Ask directly when booking, since it affects the total cost meaningfully for a solo trip.
Safety, in practice
Personal safety concerns are generally the same as for solo travel anywhere: organized excursions, licensed transport, and well-lit areas after dark cover most of it, and a guide for scheduled activities removes a lot of the usual solo-travel uncertainty. See What Should Solo Female Travelers Know Before Visiting Egypt? for more specific guidance.