3² × 7⁴

Prime Factor Structure

Factorization String 3^2 × 7^4

Distinct Prime Factors 2

Square Status Yes (√21609 = 147)

Abundance Measure Deficient

Analytical Properties

Total Divisors 15

Divisor Sum (σ) 36,413

Proper Divisor Sum 14,804

Digit Sum / Digital Root 18 (Root: 9)

Adjacent Primes #21601 ← → #21611

1 3 7 9 21 49 63 147 343 441 1,029 2,401 3,087 7,203 21,609

Iterative sequence n → n/2 (if even) or 3n+1 (if odd):

21,609 64,828 32,414 16,207 48,622 24,311 72,934 36,467 109,402 54,701 164,104 82,052 41,026 20,513 61,540 30,770 15,385 46,156 23,078 11,539 34,618 17,309 51,928 25,964 12,982 6,491 19,474 9,737 29,212 14,606 7,303 21,910 10,955 32,866 16,433 49,300 24,650 12,325 36,976 18,488 9,244 4,622 2,311 6,934 3,467 10,402 5,201 15,604 7,802 3,901 11,704 5,852 2,926 1,463 4,390 2,195 6,586 3,293 9,880 4,940

Other feeder batches with open delivery windows. Each feeder keeps its own target batch.