39 (number)

Template:Numbers 30s
Cardinal	39 thirty-nine
Ordinal	39th thirty-ninth
Factorization	$3\cdot 13$
Divisors	1, 3, 14, 39
Roman numeral	XXXIX
Binary	100111
Hexadecimal	27

39 (thirty-nine) is the natural number following 38 and preceding 40.

In mathematics

39 is the 12th distinct biprime and the 4th in the {3.q} family. It is the last member of the third distinct biprime pair (38,39).

Thirty-nine is the sum of five consecutive primes (3 + 5 + 7 + 11 + 13) and the sum of the first three powers of 3 ($3^{1}+3^{2}+3^{3}$). Given 39, the Mertens function returns 0.

39 is the smallest integer which has three partitions into three parts which all give the same product when multiplied: {25, 8, 6}, {24, 10, 5}, {20, 15, 4}.

39 has an aliquot sum of 17 which is itself a prime. 39 is the 4th member of the 17-aliquot tree

The thirteenth Perrin number is 39, which comes after 17, 22, 29 (it is the sum of the first two mentioned).

According to David Wells in The Penguin Dictionary of Curious and Interesting Numbers, 39 is the smallest mathematically uninteresting number.

In science

• The atomic number of yttrium

Astronomy

• Messier object Open Cluster M39, a magnitude 5.5 open cluster in the constellation Cygnus
• The New General Catalogue object NGC 39, a spiral galaxy in the constellation Andromeda
• The Saros number of the
  • solar eclipse series which began on -1718 May 26 and ended on -438 July 3. The duration of Saros series 39 was 1280.1 years, and it contained 72 solar eclipses.
  • lunar eclipse series which began on -1380 March 26 and ended on -82 May 14. The duration of Saros series 39 was 1298.1 years, and it contained 73 lunar eclipses.

In religion

• The number of the 39 categories of activity prohibited on Shabbat according to Halakha
• The number of mentions of work or labor in the Torah
• The actual number of lashes given by the Sanhedrin to a person meted the punishment of 40 lashes
• The number of books in the Old Testament according to Protestant canon
• The number of statements on Anglican Church doctrine, Thirty-Nine Articles

In other fields

Thirty-nine is:

• In the title of the John Buchan novel and subsequent films (one by Alfred Hitchcock), The Thirty-Nine Steps
• The code for international direct-dialed phone calls to Italy
• I-39 is the designation for a US interstate highway from Normal, Illinois to Wausau, Wisconsin. I-39 is the 39th shortest of the primary "two digit" Interstates.
• The eternal age of comedian Jack Benny, and many other people as they grow older
• The traditional number of times citizens of Ancient Rome hit their slaves when beating them, referred to as "Forty save one"
• Japanese Internet chat slang for "thank you" when written with numbers
• "'39" is a track on Queen's album A Night At the Opera. If the tracks on Queen's original studio albums are numbered in sequential order starting with their first, "'39" does in fact fall in the thirty-ninth position
• "'39" is a song by The Cure on their album "Bloodflowers"
• 39 cents was the cost of First Class US postage stamps (first ounce) from Jan. 8, 2006 to May 14, 2007
• The duration, in nanoseconds, of the nuclear reaction in the largest nuclear explosion ever performed (Tsar bomb)
• The number of Scud missiles which Iraq fired at Israel during the Gulf War in 1991
• World War II broke out in Europe on September 1 1939
• Pier 39 in San Francisco
• The retired jersey number of former baseball great Roy Campanella
• Uniform of former Pittsburgh Pirate Dave Parker
• Uniform of football's Larry Csonka of Miami Dolphins; Hugh McElhenny of the San Francisco 49ers; and Steven Jackson of the St. Louis Rams

At age 39:

• Apollo 11 commander Neil Armstrong became the 1st person to set foot on the moon
• Charles Goodyear led the way to the effective use of rubber
• Jimmy Connors reached the U.S. Open semifinals
• Joseph Smith Jr. and Martin Luther King Jr. were assassinated

Historical years

39 A.D., 39 B.C., 1939, 2039, etc. ru-sib:39 (число)