1845

1845 = 3 x 3 x 5 x 41.

1845 is a number that can be expressed as the difference of the squares of primes in just one distinct way (A090781).

1845 is the number of ways to place three points on a triangular grid of side 7 so that no two of them are adjacent (A238569).

1845 is the sum of 11 nonzero 6th powers (A003367).

1845 has two representations as a sum of two squares: 1845 = 9² + 42² = 18² + 39².

1845 divides 73⁴ - 1.

Source: OEIS