69 (number)
Encyclopedia
69 is a number following 68
and preceding 70
.
in the 13-aliquot tree.
69 is a semiprime
. Furthermore, since the two factors of 69 are both Gaussian primes, 69 is a Blum integer
.
Adding up the divisors of 1 through 9 gives 69.
Because 69 has an odd number of 1s in its binary representation, it is sometimes called an "odious number." Of note is that 69² (4 761) and 69³ (328 509) together use every decimal digit from 0-9. 69 is equal to 105
octal
, while 105 is equal to 69 hexadecimal
. This same property can be applied to all numbers from 64
to 69.
On many handheld scientific and graphing calculator
s, the highest factorial
that can be calculated, due to memory limitations, is 69 or 1.711224524.
The number 69 written in Western Arabic numeral notation can be rotated 180° and remain visually the same.
68 (number)
68 is the natural number following 67 and preceding 69.-In mathematics:Sixty-eight is a nontotient. It is also a Perrin number, preceded in the sequence by 29, 39, 51...
and preceding 70
70 (number)
70 is the natural number following 69 and preceding 71.-In mathematics:Its factorization makes it a sphenic number. 70 is a Pell number and a generalized heptagonal number, one of only two numbers to be both. Also, it is the seventh pentagonal number and the fourth 13-gonal number, as well as the...
.
In mathematics
The aliquot sum of sixty-nine is 27 within the aliquot sequence (69,27,13,1,0) 69 being the third composite numberComposite number
A composite number is a positive integer which has a positive divisor other than one or itself. In other words a composite number is any positive integer greater than one that is not a prime number....
in the 13-aliquot tree.
69 is a semiprime
Semiprime
In mathematics, a semiprime is a natural number that is the product of two prime numbers. The first few semiprimes are 4, 6, 9, 10, 14, 15, 21, 22, 25, 26, ... ....
. Furthermore, since the two factors of 69 are both Gaussian primes, 69 is a Blum integer
Blum integer
In mathematics, a natural number n is a Blum integer if n = p×q is a semiprime for which p and q are distinct prime numbers congruent to 3 mod 4. That is, p and q must be of the form 4t+3, for some integer t. Primes of this form are referred to as Blum primes. This means that the factors of a Blum...
.
Adding up the divisors of 1 through 9 gives 69.
Because 69 has an odd number of 1s in its binary representation, it is sometimes called an "odious number." Of note is that 69² (4 761) and 69³ (328 509) together use every decimal digit from 0-9. 69 is equal to 105
105 (number)
105 is the natural number following 104 and preceding 106.-In mathematics:105 is a triangular number, a 12-gonal number and a Zeisel number. It is a sphenic number, and is the product of three consecutive prime numbers. 105 is the double factorial of 7...
octal
Octal
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Numerals can be made from binary numerals by grouping consecutive binary digits into groups of three...
, while 105 is equal to 69 hexadecimal
Hexadecimal
In mathematics and computer science, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, and A, B, C, D, E, F to represent values ten to fifteen...
. This same property can be applied to all numbers from 64
64 (number)
64 is the natural number following 63 and preceding 65.-In mathematics:Sixty-four is the square of 8, the cube of 4, and the sixth power of 2. It is the smallest number with exactly seven divisors. It is the lowest positive power of two that is adjacent to neither a Mersenne prime nor a Fermat...
to 69.
On many handheld scientific and graphing calculator
Calculator
An electronic calculator is a small, portable, usually inexpensive electronic device used to perform the basic operations of arithmetic. Modern calculators are more portable than most computers, though most PDAs are comparable in size to handheld calculators.The first solid-state electronic...
s, the highest factorial
Factorial
In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n...
that can be calculated, due to memory limitations, is 69 or 1.711224524.
The number 69 written in Western Arabic numeral notation can be rotated 180° and remain visually the same.
Astronomy
- The Messier objectMessier objectThe Messier objects are a set of astronomical objects first listed by French astronomer Charles Messier in 1771. The original motivation of the catalogue was that Messier was a comet hunter, and was frustrated by objects which resembled but were not comets...
M69Messier 69Messier 69 is a globular cluster in the constellation Sagittarius. It was discovered by Charles Messier on August 31, 1780, the same night he discovered M70...
is a magnitude 9.0 globular clusterGlobular clusterA globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
in the constellationConstellationIn modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
SagittariusSagittarius (constellation)Sagittarius is a constellation of the zodiac, the one containing the galactic center. Its name is Latin for the archer, and its symbol is , a stylized arrow. Sagittarius is commonly represented as a centaur drawing a bow...
.
In other fields
Sixty-nine may also refer to:- The registry of the U.S. Navy's aircraft carrier USS Dwight D. Eisenhower (CVN-69)USS Dwight D. Eisenhower (CVN-69)USS Dwight D. Eisenhower is an aircraft carrier currently in service with the United States Navy. Commissioned in 1977, the ship is the second of the ten Nimitz-class supercarriers currently in service, and is the first ship named after the thirty-fourth President of the United States, Dwight D....
, named after Dwight D. Eisenhower, the 34th President of the United States and five-star general in the United States Army - The number of the French department Rhône
- The TaijituTaijituTaijitu is a term which refers to a Chinese symbol for the concept of yin and yang...