72 (
seventy-two) is the
natural number following
71 and preceding
73.
It is half a
gross or 6
dozen (i.e., 60 in
duodecimal).
In mathematics
Seventy-two is the sum of four consecutive
primes (13 + 17 + 19 + 23), as well as
the sum of six consecutive primes (5 + 7 + 11 + 13 + 17 + 19). The
product of 8 and 9, 72 is a
pronic
number. And as a multiple of a
perfect number, 72 is itself a
semiperfect number.
The sum of
Euler's totient
function φ(
x) over the first fifteen integers is 72.
There are 17 solutions to the equation φ(
x) = 72, more
than any integer below 72, making it a
highly totient number.
72 is the smallest number whose fifth power is the sum of 5 smaller
fifth powers; 19
^{5} + 43
^{5} + 46
^{5} +
47
^{5} + 67
^{5} = 72
^{5}
The sum of the eighth row of
Lozanić's triangle is 72.
In a plane, the
exterior angles of a
regular
pentagon measure 72 degrees
each.
In base 10, the number 72 is a
Harshad
number.
In science
- The atomic number of hafnium
- In degrees Fahrenheit considered to be room temperature.
- The average number of heartbeats per minute for a resting
adult.
- Percentage of water of which the human body is composed.
- The life duration of the ovule is 72 hours.
- The mass of the Moon is 1/72nd of that the Earth.
- The volume of Saturn is 72 times of that the Earth.
- The axis of the earth moves of one degree every 72 years
compared to stars and to the vault of heaven.
In astronomy
In religion
- The conventional number of scholars translating the Septuagint, according to the legendary account in
the "Letter of Aristeas".
- The conventional number of disciples sent forth by Jesus in
Luke 10 in some manuscripts (seventy in others).
- The number of hours Jesus was in the grave, before rising
again.
- The number of names of God, according to Kabbalah (see names of God in Judaism).
- The Shemhamphorasch related to
the number of the names of God.
- The total number of books in the Holy
Bible in the Catholic version if the
Book of Lamentations is considered part of the Book of
Jeremiah.
- The current distribution of the Revelation book is 22 chapters,
adopted since the 13th century. But such was not always the case.
The oldest known division of the text is that the Greek commentator
Andrew of Cesary (6th century) in 72 chapters. Although made with
enough accuracy, this structuring could be easily reduced to 70,
while putting in the same chapter, the numbers 60, 61 and 62 which
constitute a whole, the millennial Reign. Andrew had wanted
moreover group these 72 chapters three by three, in order to obtain
24 sections, corresponding to the 24 old mans. These 24 sections
were completely arbitrary, and divided the texts at the wrong
moment. Let us mention that the Codex Amiatinus and the Codex
Fuldensis share the book of the Revelation in 25 chapters, and that
some Latin handwritten find some from 22 to 44.
- The
number of warriors on the Muslim side at the Battle of Badr.
- The number of people martyred along with Imam Hussain at the Battle of Karbala.
- The number of soldiers who will fight alongside Imam Mahdi against the Dajjal,
according to Islamic ahadith.
- The number of devils according to The Lesser Key of Solomon.
- The 72 old men of the synagogue, according to the Zohar.
- The degrees of the Jacob's ladder were to the number of 72,
according to the Zohar.
- The 72 disciples of Confucius.
- The good God Osiris was enclosed in a
coffin by 72 evil disciples and accomplices of Set.
- It is the number of the Immortals Taoism.
- At the age of the puberty, the young Parsee received the
investiture of the sacred cord Kucti made of 72 linens in symbol of
the community.
In other fields
Seventy-two is also:
- The ASCII code for 'H'
- The number of hours in 3 days.
- In dpi, the standard resolution of an
Apple Macintosh screen.
- The number of the French department Sarthe.
- The
designation of USA Interstate 72, a
freeway that runs from Missouri to Illinois, East >
West.
- Municipal Okrug
72, a municipal okrug of Frunzensky District of Saint
Petersburg,
Russia
- The registry of the U.S. Navy's nuclear aircraft carrier USS Abraham
Lincoln , named after U.S. President Abraham Lincoln.
- The designation of the Soviet T-72
tank.
- In the movie The Red
Violin, the lot number of the Bussotti red violin at the
DuVal auction house.
- The year AD 72, 72 BC, 1972, or any other year
ending with "72".
- The Rule of 72 in finance.
- A loud tone of 72Hz makes light
objects vibrate.
- Book: 72 Hour Hold by Bebe Moore Campbell
- CD: Seventy Two & Sunny by Uncle Kracker
- Jill Clayburgh and LeVar Burton starred in Firestorm: 72 Hours
in Oakland (1993)
- Alternative music band The Delta
72
- New
York's Dakota
Apartments and Strawberry Fields are by 72nd St. and
Central Park West
- The "sentûr" Persian has 72 cords, three by note.
- The number of episodes in the original airing of Futurama.
- The Turin Brakes song, also known
as Emergency 72
In sports and games
- The usual par for an 18 hole golf course,
especially those in tournament play.
- The number of victories the Chicago
Bulls got in the 1995-96 NBA
season, which is the NBA record.
- Heavyweight boxer Joe Louis fought 72
fights (69-3)
- While playing for the Chicago
White Sox, Carlton Fisk wore #72.
This was the inverse of the 27 he wore
with the Boston Red Sox since that
number was not available when he arrived in Chicago.
- Former NFL defensive tackle William Perry, most
famously of the 1985 Chicago
Bears, wore #72.
- King Of The Hill character Bill
Daughtreve is often shown wearing #72 during his high school
football playing days. The character's high school career shares
many of the same elements as Perry's pro career.
- The number of spaces in a game of Parcheesi, from start space to "home."
- The number of tiles in the original base game of the popular
Carcassonne .
- The number of Stefan Everts, 10
time world
champion in the sport of motocross
- The year of the famous hockey summit series between Canada and
USSR, commonly referred to as the '72 series
Footnotes