# 197

This number is a prime. The only three-digit prime repfigit number. [Trotter] 197 and 2197 * 197# - 1 are primes. [Boland] The first three digits of the prime 197 * 197! + 1 are 197. [Luhn] Surrey and England batsman Jack Hobbs scored a record 197 centuries. The sum of the first dozen primes. [Brod] The smallest prime number that is the sum of 7 consecutive prime numbers (17+19+23+29+31+37+41). [Schuler] 197 is the sum of digits of all two-digit primes. [Gallardo] The smallest multidigit prime p that makes 10^p-9 prime. Note that the next prime (199) has the same property. They are twin primes! [Gallardo] This prime is the smallest number to be the sum of repdigits of its digits: 111 + 9 + 77 = 197. [Post] The sum of the squares of all the four composite digits (4^2 + 6^2 + 8^2 + 9^2). [Silva] The digits contained in two-digit primes under 100, up to 97, sum to 100+97. [Silva] 19 x 7 + (1 x 9 x 7) + 1 = 197. [Homewood]

(There are 9 curios for this number that have not yet been approved by an editor.)