Factors of 399

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What are the Factors of 399?

Answer

Factors of 399:

1, 3, 7, 19, 21, 57, 133, 399

8 factors · 399 = 3 × 7 × 19 · composite

Underlined — prime: 3, 7, 19 · 1 — neither prime nor composite · others — composite

Factor pairs of 399

4 pairs: 1 × 399 · 3 × 133 · 7 × 57 · 19 × 21

Past √399 ≈ 19.97 every pair would repeat one already found — so checking stops at 19.

399 = 3 × 7 × 19 → (1 + 1) × (1 + 1) × (1 + 1) = 8 factors: add 1 to each exponent and multiply.

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See Also

Prime Number Checker - Find out whether a given number is Prime or not
Prime Factorization - Prime Factorization Calculator
Prime Numbers List - List of all Prime Numbers - how many Prime numbers are between

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Factors Table

Number	Factors
384	1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192, 384
385	1, 5, 7, 11, 35, 55, 77, 385
386	1, 2, 193, 386
387	1, 3, 9, 43, 129, 387
388	1, 2, 4, 97, 194, 388
389	1, 389
390	1, 2, 3, 5, 6, 10, 13, 15, 26, 30, 39, 65, 78, 130, 195, 390
391	1, 17, 23, 391
392	1, 2, 4, 7, 8, 14, 28, 49, 56, 98, 196, 392
393	1, 3, 131, 393
394	1, 2, 197, 394
395	1, 5, 79, 395
396	1, 2, 3, 4, 6, 9, 11, 12, 18, 22, 33, 36, 44, 66, 99, 132, 198, 396
397	1, 397
398	1, 2, 199, 398
399	1, 3, 7, 19, 21, 57, 133, 399
400	1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 200, 400
401	1, 401
402	1, 2, 3, 6, 67, 134, 201, 402
403	1, 13, 31, 403
404	1, 2, 4, 101, 202, 404
405	1, 3, 5, 9, 15, 27, 45, 81, 135, 405
406	1, 2, 7, 14, 29, 58, 203, 406
407	1, 11, 37, 407
408	1, 2, 3, 4, 6, 8, 12, 17, 24, 34, 51, 68, 102, 136, 204, 408
409	1, 409
410	1, 2, 5, 10, 41, 82, 205, 410
411	1, 3, 137, 411
412	1, 2, 4, 103, 206, 412
413	1, 7, 59, 413

FAQ

What are the Factors of 399?

Factors of 399: 1, 3, 7, 19, 21, 57, 133, 399

How many factors does 399 have?

Number 399 has 8 factors

How many Factor Pairs does 399 have?

Number 399 has 4 factor pairs

Is 399 a prime or composite number?

Composite: 399 = 3 × 7 × 19, so it has 8 factors — a prime has exactly two.

How many factors does 399 have excluding 1 and 399?

6: 3, 7, 19, 21, 57 and 133.