For the year A.D. 39, see 39.
Thirty-nine (39, XXXIX) is the natural number following thirty-eight and preceeding forty. Its divisors are 1, 3, 13, and 39; its factorisation is
Thirty-nine is also:
- The atomic number of yttrium.
- In the title of the John Buchan, novel The Thirty-Nine Steps.
- The code for international direct-dialed phone calls to Italy.
- The eternal age of comedian Jack Benny, and many other people as they grow older.
Thirty-seven - Thirty-eight - Thirty-nine - Forty - Forty-one