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LCM(1…7)

420

integer
Calculated

Least common multiple of the first seven positive integers

The smallest number that 1, 2, 3, 4, 5, 6 and 7 all divide is 420. It has exactly 24 positive divisors, and 42 is one of them. Seven factorial is 5,040, twelve times larger. Same family of sevens. Not Plato’s tribes.

What it supports

An exact arithmetic identity anyone can check: 2² × 3 × 5 × 7 = 420. Distinct from 5,040 ÷ 12 = 420. Two operations, one integer, two cards.

What it does not

Not 42. Not a calendar proof. Not Plato’s city. 420 is ten times 42 and remains a different family.

Calculation

2² × 3 × 5 × 7 = 420

Prime-factor lcm of 1 through 7

ExactnessExact

Form420

Unitinteger

Strengthhard

Source

The Book of 42 · /mathematics#lcm-420

Owner

The Book of 42