390,640

2⁴ × 5 × 19 × 257

390,640 has digital root 4. The neighboring primes are 390581 and 390647; its proper-divisor sum differs from the starting integer by 178,480.

Prime Factor Structure

Factorization String 2^4 × 5 × 19 × 257

Distinct Prime Factors 4

Square Status No

Abundance Measure Abundant

Analytical Properties

Total Divisors 40

Divisor Sum (σ) 959,760

Proper Divisor Sum 569,120

Digit Sum / Digital Root 22 (Root: 4)

Adjacent Primes #390581 ← → #390647

Radix Representation

Decimal	390640
Binary	1011111010111110000 (19 bits)
Octal	0o1372760
Hexadecimal	0x5F5F0

Divisor Catalog (40)

1 2 4 5 8 10 16 19 20 38 40 76 80 95 152 190 257 304 380 514 760 1,028 1,285 1,520 2,056 2,570 4,112 4,883 5,140 9,766 10,280 19,532 20,560 24,415 39,064 48,830 78,128 97,660 195,320 390,640

Collatz Trajectory (161 steps to reach 1)

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

390,640 195,320 97,660 48,830 24,415 73,246 36,623 109,870 54,935 164,806 82,403 247,210 123,605 370,816 185,408 92,704 46,352 23,176 11,588 5,794 2,897 8,692 4,346 2,173 6,520 3,260 1,630 815 2,446 1,223 3,670 1,835 5,506 2,753 8,260 4,130 2,065 6,196 3,098 1,549 4,648 2,324 1,162 581 1,744 872 436 218 109 328 164 82 41 124 62 31 94 47 142 71

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