a
Harshad number in bases 6, 8, 9, 10, 11, 13, 14, 15 and 16.
an
Erdős–Woods number, since it is possible to find sequences of 70 consecutive integers such that each inner member shares a factor with either the first or the last member.[6]
The sum of the first 24 squares starting from 1 is 702 = 4900, i.e. a square pyramidal number. This is the only non trivial solution to the
cannonball problem and relates 70 to the
Leech lattice and thus
string theory.
Psalm 90:10 allots three score and ten (70 years) for a man's life, and the
Mishnah attributes that age to "strength" (Avot
5:32), as one who survives that age is described by the verse as "the strong".
Ptolemy II Philadelphus ordered 72 Jewish elders to translate the
Torah into
Greek; the result was the
Septuagint (from the
Latin for "seventy"). The Roman numeral seventy, LXX, is the scholarly symbol for the Septuagint.
70
miles per hour is a common
speed limit for freeways in many
American states, primarily in the central United States (in the Eastern U.S. the speed limit is generally 65, in the Western U.S. it is 75).
Under
Social Security (United States), the age at which a person can receive the maximum retirement benefits (and may do so and continue working without reduction of benefits)
Several languages, especially ones with
vigesimal number systems, do not have a specific word for 70: for example,
French: soixante-dix,
lit. 'sixty-ten';
Danish: halvfjerds, short for halvfjerdsindstyve, 'three and a half score'. (For French, this is true only in France; other French-speaking regions such as
Belgium,
Switzerland,
Aosta Valley and
Jersey use septante.[8])
^The Official Highway Code, pub. Department for Transport (Revised 2007 Edition).
ISBN978-0-11-552814-9. A white circular sign with a black diagonal stripe indicates that the national speed limit applies. This depends on the vehicle type and grade of road. The table on p. 40 shows the highest speed permitted to be 70 mph, for normally-laden cars and motorcycles on dual-carriageways and motorways.
^Peter Higgins, Number Story. London: Copernicus Books (2008): 19. "Belgian French speakers however grew tired of this and introduced the new names septante, octante, nonante etc. for these numbers".
External links
Look up seventy in Wiktionary, the free dictionary.