420 (number)

Short description: Natural number

← 419 420 421 →
List of numbers — Integers ← 0 100 200 300 400 500 600 700 800 900 →
Cardinal	four hundred twenty
Ordinal	420th (four hundred twentieth)
Factorization	22 × 3 × 5 × 7
Greek numeral	ΥΚ´
Roman numeral	CDXX
Binary	1101001002
Ternary	1201203
Quaternary	122104
Quinary	31405
Senary	15406
Octal	6448
Duodecimal	2B012
Hexadecimal	1A416
Vigesimal	11020
Base 36	BO36

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]\displaystyle{ 101+103+107+109 }[/math]).
• the sum of the first twenty positive even numbers.
• a zero of the Mertens function and is sparsely totient.
• a pronic number.
• 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.

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.