70 (number)
70 is the natural number following 69 and preceding 71.
Mathematics
70 is a composite number an Erdős–Woods number, a Pell number, a central binomial coefficient, and a primitive abundant number. 70 is the smallest weird number, which is a natural number that is abundant but not semiperfect.70 is also part of the only nontrivial solution pair to the cannonball problem, along with 24.
In religion
- In Jewish tradition, Ptolemy II Philadelphus ordered 72 Jewish elders to translate the Torah into Greek; the result was the Septuagint. The Roman numeral seventy, LXX, is the scholarly symbol for the Septuagint.
- In Islamic history and in Islamic interpretation the number 70 or 72 is most often and generally hyperbole for an infinite amount:
- * There are 70 dead among Muhammad's adversaries during the Battle of Badr.
- * 70 of Muhammad's followers are martyred at the Battle of Uhud.
- * In Shia Islam, there are 70 martyrs among Imam Hussein's followers during the Battle of Karbala.
In other fields
- In some traditions, 70 years of marriage is marked by a platinum wedding anniversary.
- Under Social Security (United States), the age at which a person can receive the maximum retirement benefits.