42 (number)

← 41 42 43 →
Cardinalforty-two
Ordinal42nd
(forty-second)
Factorization2 × 3 × 7
Greek numeralΜΒ´
Roman numeralXLII
Binary1010102
Ternary11203
Quaternary2224
Quinary1325
Senary1106
Octal528
Duodecimal3612
Hexadecimal2A16
Vigesimal2220
Base 361636

42 (forty-two) is a number. It comes between forty-one and forty-three, and is an even number. It is divisible by 1, 2, 3, 6, 7, 14, 21, and 42.

42 is an extremely interesting number to mathematicians, because of its many features. For example:

  1. It is the product of two consecutive integers (6 and 7), making it a pronic number.
  2. It is the second sphenic number, the product of three distinct prime numbers.
  3. It is an abundant number, the sum of its proper divisors is greater than the number itself.

There are at least a dozen more features of interest to number theory enthusiasts.

Appearance in literature

"42" is the "Answer to the Ultimate Question of Life, the Universe, and Everything" in Douglas Adams' The Hitchhiker's Guide to the Galaxy books.

The number makes regular appearances in Lewis Carroll's writings, such as in The Hunting of the Snark. Rule Forty-two in Alice's Adventures in Wonderland is "All persons more than a mile high to leave the court". Charles Dodgson was a mathematician.