Sum of all 3-digit numbers (digits non-zero) where all digits are perfect squares.

Digits that are perfect squares (non-zero): 1, 4, 9 Three-digit numbers using {1,4,9}: Total = 3 × 3 × 3 = 27 3×3×3=27 numbers Sum of digits = 1 + 4 + 9 = 14 1+4+9=14 Each digit appears 9 times in each position (hundreds, tens, units). Total sum = 100 × 9 × 14 + 10 × 9 × 14 + 1 × 9 × 14 100×9×14+10×9×14+1×9×14 = 111 × 9 × 14 111×9×14 = 999 × 14 999×14 = 13986