Number dictionary · Exact arithmetic

520: factors and number facts

five hundred twenty is an even number and is composite. Its 16 positive divisors form 8 factor pairs.

Number JD Editorial Team · Updated 2026-10-08

In words
five hundred twenty
Roman numeral
DXX
Prime factorization
2^3 × 5 × 13
Digital root
7

All factors of 520

A positive factor divides 520 with no remainder. In ascending order, the complete list is:

1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 104, 130, 260, 520

Factor pairs

  • 1 × 520 = 520
  • 2 × 260 = 520
  • 4 × 130 = 520
  • 5 × 104 = 520
  • 8 × 65 = 520
  • 10 × 52 = 520
  • 13 × 40 = 520
  • 20 × 26 = 520

Each pair describes an arrangement of 520 items into equal rows. The pairs have different row and column counts; 520 cannot make a square array of whole items.

Divisor totals

Positive divisors
16
Sum of all divisors
1260
Sum excluding 520
740
Classification
abundant

520 is abundant because its proper divisors add to 740, which is greater than 520.

Understand factors and multiples

Prime factorization of 520

520 = 2^3 × 5 × 13

Repeated division, step by step

  1. 520 ÷ 2 = 260
  2. 260 ÷ 2 = 130
  3. 130 ÷ 2 = 65
  4. 65 ÷ 5 = 13
  5. 13 ÷ 13 = 1

Multiply the prime divisors in these steps to reconstruct 520. An exponent records how many times the same prime occurs. The divisor-count calculation is (3 + 1) × (1 + 1) × (1 + 1) = 16.

The preceding prime is 509. The next larger prime is 521. The factor list above explains why 520 is composite.

Learn the factorization method

520 in words, Roman numerals and other bases

Equivalent representations of the integer 520
RepresentationValue
English (US style)five hundred twenty
Roman numeralDXX
Binary (base 2)1000001000
Octal (base 8)1010
Decimal (base 10)520
Hexadecimal (base 16)208

Check the binary conversion

Read 1000001000 from right to left using place values 1, 2, 4, 8 and successive powers of two. Keep the values whose bit is 1:

512 + 8 = 520

Check the hexadecimal conversion

2 × 16^2 + 0 × 16^1 + 8 × 16^0 = 520

Hexadecimal uses A through F for digit values 10 through 15. These notations represent the same quantity; changing the base does not change the integer.

Square, cube and square root of 520

520 squared
520 × 520 = 270,400
520 cubed
520 × 520 × 520 = 140,608,000
Square root
≈ 22.803509
Simplified radical
2√130

520 lies between 484 (22²) and 529 (23²), so it is not a perfect square. It is not a perfect cube.

520 is not triangular: no positive whole-number k satisfies k(k + 1) / 2 = 520.

Distinguish a square from a square root

Multiplication table for 520

These are the first twelve positive multiples. Unlike the finite factor list, the sequence of multiples continues without an upper limit.

520 × 1520
520 × 21,040
520 × 31,560
520 × 42,080
520 × 52,600
520 × 63,120
520 × 73,640
520 × 84,160
520 × 94,680
520 × 105,200
520 × 115,720
520 × 126,240

Divisibility checks

Quotients and remainders for divisors 2 through 12
Divide byWhole quotientRemainderDivides exactly?
22600Yes
31731No
41300Yes
51040Yes
6864No
7742No
8650Yes
9577No
10520Yes
11473No
12434No

For example, 520 = 7 × 74 + 2. A remainder of zero is what makes a divisor a factor.

Digit sum and digital root of 520

520 contains 3 decimal digits. Its digit sum is 5 + 2 + 0 = 7.

  1. 520: 5 + 2 + 0 = 7

The digital root is 7. Reversing its digits gives 025; it is not a decimal palindrome. Digit patterns depend on the notation being used.

Digital-root arithmetic always finishes at a single digit for a positive integer. Some numerology methods stop at 11, 22 or 33 instead; that is a separate interpretive convention.

Fractions and a worked comparison

As a fraction of 100, 520/100 simplifies to 26/5 by dividing both terms by their greatest common divisor, 20. Its decimal value is 5.2. Because the numerator exceeds the denominator, this value is greater than one.

The greatest common divisor of 520 and 12 is 4. Their least common multiple is 1560. The identity GCD × LCM = 520 × 12 = 6240 checks both results.

Work through GCF and LCM

Questions about 520

What are the factors of 520?

The positive factors are 1, 2, 4, 5, 8, 10, 13, 20, 26, 40, 52, 65, 104, 130, 260, 520. There are 16 factors, including 1 and 520.

Is 520 a prime number?

No. 520 is composite: 2^3 × 5 × 13 = 520.

How do you write 520 in Roman numerals?

520 is DXX in standard subtractive Roman numeral notation.

What is the binary representation of 520?

520 in decimal is 1000001000 in base 2. Adding its active place values gives 512 + 8 = 520.

Methods and reference definitions

Number JD calculates each result from the integer on this page. Positive factors are enumerated in pairs; repeated division gives the prime factorization; place values verify base conversions. Decimal square roots are rounded to six places when irrational.

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A reflective note on 520

Meaning varies by tradition and personal experience. One sighting is not evidence of what will happen next.

The digits of 520 add to 7. That arithmetic result is separate from the cultural symbolism of the pattern. If this number matters to you, write down what you noticed and choose one grounded action rather than treating the sighting as a prediction.