6,355,441

Number
$6 \, 355 \, 441$ (six million, three hundred and fifty-five thousand, four hundred and forty-one) is:


 * $2521^2$


 * The $2521$st square number:
 * $6 \, 355 \, 441 = 2521 \times 2521$


 * The $1456$th centered hexagonal number:
 * $6 \, 355 \, 441 = 3 \times 1456 \times \left({1456 - 1}\right) + 1 = 1456^3 - 1455^3$


 * The $4$th centered hexagonal number after $1, 169, 32 \, 761$ which is also square:
 * $6 \, 355 \, 441 = 1456^3 - 1455^3 = 2521^2$