39 (number)

39
Cardinal thirty-nine
Ordinal 39th
(thirty-ninth)
Factorization  3 \cdot 13
Divisors 1, 3, 13, 39
Roman numeral XXXIX
Binary 1001112
Octal 478
Duodecimal 3312
Hexadecimal 2716

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

Contents

In mathematics

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 %2B 3^2 %2B 3^3). Given 39, the Mertens function returns 0.

39 is the smallest natural number 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 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).

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 Størmer number.

The F26A graph is a symmetric graph with 39 edges.

In science

Astronomy

In religion

In other fields

Arts and entertainment
History
Other

Historical years

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