4347 = 3 x 3 x 3 x 7 x 23.
4347 is a heptagonal number (A000566). It is also a pentagonal number (A049452).
4347 is the concatenation of the 27th and 28th primes (A045533).
4347 is a value of n for which 2n and 5n together use each of the digits 1 to 9 exactly once.
4347 is the number of regions in a regular 63-gon that are octagons (A067155).
4347 divides 2218 - 1.
Source: Number Gossip