906 = 2 x 3 x 151.
906 is the number of perfect graphs with 7 vertices.
906 = 25 x 33 + 42.
906 is an even number that is not the sum of a pair of twin primes (A007534).
906 is a number n such that the concatenation 2n3n5n7n11n13 is a prime (A092117).
906 is a strobogrammatic cyclops number (A153806).
Source: What's Special About This Number?