947

This number is a prime.

The telephone area code for Oakland County, Michigan. Interestingly, the words "Telephone code Oakland" have, respectively, 9, 4 and 7 digits. [Hartley]

The smallest prime nontrivial partial sum of holey primes: 89 + 409 + 449 = 947 is prime. [Post]

The largest 3-digit prime whose absolute value of the differences between any two of its digits are also prime. Note that 947 is the sum of first three consecutive primes in the sequence of primes with this property, i.e., 163+257+461. [Loungrides]

The only 3-digit left-truncatable prime whereby removing the last digit gives double the number obtained by removing the first. [Leonardis]

947²=896809 is the smallest circular-digit prime square containing all possible circular digits (0, 6, 8, 9). It also contains as substrings the Cyclops prime 809 and its "blinded" cousin 89. [Leonardis]