420 (number)

In mathematics

• the sum of four consecutive primes.
• the sum of the first twenty positive even numbers.
• a zero of the Mertens function and is sparsely totient.
• a pronic number.
• The least common multiple of numbers from 1 through 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.
• largely composite number

In other fields

• The international country code for Czech Republic.
• 420 is also cannabis culture slang for cannabis consumption.