39 (number): Map

Map showing all locations mentioned on Wikipedia article:

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

In mathematics

39 is the 12th distinct semiprime 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).

Since the greatest prime factor of 392 + 1 = 1522 is 761, which is obviously more than 39 twice, 39 is a StÃ¸rmer number.

According to David Wells in The Penguin Dictionary of Curious and Interesting Numbers, 39 is the smallest mathematically uninteresting number. The book claims that it is also the first number that is simultaneously both interesting and uninteresting, thereby avoiding the paradox.

In other fields

Arts and entertainment

History
• The number of signers to the United States Constitution, out of 55 members of the Philadelphia Convention delegates
• The traditional number of times citizens of Ancient Rome hit their slaves when beating them, referred to as "Forty save one"
• 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

Other

At age 39

Historical years

39 A.D., 39 B.C., 1939, 2039, etc.

 Embed code: