2209

Number
$2209$ (two thousand, two hundred and nine) is:


 * $47^2$


 * The $47$th square number after $1, 4, 9, 16, 25, 36, \ldots, 1296, 1369, 1444, 1521, 1600, 1681, 1764, 1936, 2025, 2116$:
 * $2209 = 47 \times 47$


 * The $41$st positive integer which cannot be expressed as the sum of a square and a prime:
 * $1, 10, 25, 34, 58, 64, 85, \ldots, 1024, 1089, 1225, 1255, 1351, 1414, 1444, 1521, 1681, 1849, 1906, 1936, 2116, 2209, \ldots$