# 1973

This number is a prime.

N.J.A. Sloane's *A Handbook of Integer Sequences* was
first published by Academic Press in 1973.

The smallest prime formed by using all possible end digits of multidigit primes, i.e., 1, 3, 7, and 9. [Gupta]

1973 is the year Picasso died. [Stroup]

The least prime p that becomes composite if we add or subtract any power of 2 less than p/2. (The next few are 3181, 3967, 4889, 8363, 8923, ...) [TT2011]. [Caldwell]

The smallest diagonal prime with distinct digits. (A diagonal prime is a prime of n^2 digits (n > 1) arranged left-right, top-down in a n-by-n matrix, where the diagonals are prime in each direction). [Loungrides]

If we examine the possible end digits of the first million primes, then "1" occurs the least, followed by "9", then "7", with "3" occurring the most. [Honaker]

The term "factoid" was coined in 1973 by American writer Norman Mailer.

Mr. Prime Beef has been serving Alaskan communities since 1973.

A 1973 stamp encouraged people to use the ZIP Code on letters and parcels.