2991

2991 = 3 x 997.

2991 is the smallest number with two prime factors summing to 1000—with three digits the same as the previous number (2491) with prime factors summing to a power of ten: 2491 = 47 x 53.

2991 is a number that cannot be written as the sum of three squares.

2991 is a semiprime that is not the sum of three pentagonal numbers.

Lego set 2991 features Pooh and the Honeybees.

Source: Prime Curios!