"utterly intriguing" is correct and usable in written English.
You can use it to describe something that is so interesting or mysterious that it captures your attention. For example, you could say "The story was utterly intriguing; I couldn't stop reading until I reached the end."
It was utterly intriguing, with audacious flourishes of suspense.
It helps that it's an utterly intriguing subject: what defines us as human?
The revelation of exactly what it is that she is trying to escape and why she intends to end her life is gradual and utterly intriguing.
RICHARD VALERIANI Sherman, Conn., June 14 , 2011To the Editor: As an independent voter, disgusted with the shallow caterwauling of the two parties, I find David Brooks's invocation of a (hypothetical) Hamiltonian Party utterly intriguing.
Carol Morley's The Falling is beguiling and disturbing, a beautifully made and very subtle affair that combines melodrama, rites of passage and supernatural elements in an utterly intriguing way.
Gloria, making her own inquiries, finds that a number of those present on the night of the original tragedy have either killed themselves or had remarkably bad luck in life... Set in rural Scotland, The Child Garden is both utterly intriguing and disturbingly eerie.
This long opening sequence of The Americans (ITV, Saturday) is pumped up, intriguing and utterly, utterly baffling.
It is utterly gripping and intriguing, and will have you lying awake puzzling and worrying.
Over the past decade, metallic nanoparticles with large surface-to-volume ratios have attracted steadily growing scientific interest because of their utterly novel characteristics and intriguing applications that are complementary or superior to those of bulk materials [1].
These accuracies, big and small, and the intriguing but again, utterly authentic twists in the agency story, began to warm the initial sceptics.
Steam Rice Crepe, six compact rice paper rolls of ground pork and mushrooms, half-moon slices of soft Vietnamese sausage under toasted onion shreds (a brilliant, traditional touch), cucumber and crisp bean sprouts, was utterly different but just as intriguing.
