Английская Википедия:420 (number)
Материал из Онлайн справочника
Шаблон:Other uses Шаблон:More citations needed Шаблон:Infobox number 420 (four hundred [and] twenty) is the natural number following 419 and preceding 421.
In mathematics
420 is:
- the sum of four consecutive primes (<math>101+103+107+109</math>).
- the sum of the first twenty positive even numbers.
- a zero of the Mertens function[1] and is sparsely totient.[2]
- a pronic number.[3]
- the smallest number divisible by the numbers 1 to 7; as a consequence of that, it is a Harshad number in bases 2 to 10, except in base 5.
- a 141-gonal number.
- a balanced number.[4]
In other fields
- 420 is a slang term that refers to the consumption of cannabis. April 20th is commonly celebrated as a holiday dedicated to the drug, due to the numerical form of the day being 4/20.
- 420 is the country calling code for Czech Republic.
References
Шаблон:Reflist Шаблон:Integers
