42 = 2 x 3 x 7.
42 = 6 x 7, it is a pronic, oblong, rectangular or heteromecic number. This is the best excuse I can think of to consume an oblong biscuit that has been dunked in a nice cup of tea.
42 is a sphenic number, thus it has exactly eight divisors.
42 is a self number.
42 = 19 + 23, the sum of two consecutive primes.
42 is the sixth cake number.
42 is a Catalan number, which means that, amongst other things, it is the number of ways:
- that a seven sided polygon can be cut into five triangles;
- that parentheses can be placed in a sequence of six numbers to be multiplied, two at a time;
- that paths of length 10 can pass through a 5-by-5 grid while not rising above the main diagonal.
42 is the number of minutes it would take to fall through a hole bored through the planet Earth.
42 is, of course, The Answer To The Ultimate Question Of Life, The Universe, And Everything.