(prime-factors 1024)
   → (2 2 2 2 2 2 2 2 2 2)

(lib 'bigint)
;; 2^59 - 1
(prime-factors (1- (expt 2 59)))
    → (179951 3203431780337)

(prime-factors 100000000000000000037)
    → (31 821 66590107 59004541)