Number dictionary · Exact arithmetic

989: factors and number facts

nine hundred eighty-nine is an odd number and is composite. Its 4 positive divisors form 2 factor pairs.

Number JD Editorial Team · Updated 2026-10-08

In words
nine hundred eighty-nine
Roman numeral
CMLXXXIX
Prime factorization
23 × 43
Digital root
8

All factors of 989

A positive factor divides 989 with no remainder. In ascending order, the complete list is:

1, 23, 43, 989

Factor pairs

  • 1 × 989 = 989
  • 23 × 43 = 989

Each pair describes an arrangement of 989 items into equal rows. The pairs have different row and column counts; 989 cannot make a square array of whole items.

Divisor totals

Positive divisors
4
Sum of all divisors
1056
Sum excluding 989
67
Classification
deficient

989 is deficient because its proper divisors add to 67, which is less than 989.

Understand factors and multiples

Prime factorization of 989

989 = 23 × 43

Repeated division, step by step

  1. 989 ÷ 23 = 43
  2. 43 ÷ 43 = 1

Multiply the prime divisors in these steps to reconstruct 989. Each prime in this factorization occurs once. The divisor-count calculation is (1 + 1) × (1 + 1) = 4.

The preceding prime is 983. The next larger prime is 991. The factor list above explains why 989 is composite.

Learn the factorization method

989 in words, Roman numerals and other bases

Equivalent representations of the integer 989
RepresentationValue
English (US style)nine hundred eighty-nine
Roman numeralCMLXXXIX
Binary (base 2)1111011101
Octal (base 8)1735
Decimal (base 10)989
Hexadecimal (base 16)3DD

Check the binary conversion

Read 1111011101 from right to left using place values 1, 2, 4, 8 and successive powers of two. Keep the values whose bit is 1:

512 + 256 + 128 + 64 + 16 + 8 + 4 + 1 = 989

Check the hexadecimal conversion

3 × 16^2 + 13 × 16^1 + 13 × 16^0 = 989

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 989

989 squared
989 × 989 = 978,121
989 cubed
989 × 989 × 989 = 967,361,669
Square root
≈ 31.448370
Simplified radical
√989

989 lies between 961 (31²) and 1024 (32²), so it is not a perfect square. It is not a perfect cube.

989 is not triangular: no positive whole-number k satisfies k(k + 1) / 2 = 989.

Distinguish a square from a square root

Multiplication table for 989

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

989 × 1989
989 × 21,978
989 × 32,967
989 × 43,956
989 × 54,945
989 × 65,934
989 × 76,923
989 × 87,912
989 × 98,901
989 × 109,890
989 × 1110,879
989 × 1211,868

Divisibility checks

Quotients and remainders for divisors 2 through 12
Divide byWhole quotientRemainderDivides exactly?
24941No
33292No
42471No
51974No
61645No
71412No
81235No
91098No
10989No
118910No
12825No

For example, 989 = 7 × 141 + 2. A remainder of zero is what makes a divisor a factor.

Digit sum and digital root of 989

989 contains 3 decimal digits. Its digit sum is 9 + 8 + 9 = 26.

  1. 989: 9 + 8 + 9 = 26
  2. 26: 2 + 6 = 8

The digital root is 8. 989 reads the same forward and backward, making it 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, 989/100 simplifies to 989/100 by dividing both terms by their greatest common divisor, 1. Its decimal value is 9.89. Because the numerator exceeds the denominator, this value is greater than one.

The greatest common divisor of 989 and 12 is 1. Their least common multiple is 11868. The identity GCD × LCM = 989 × 12 = 11868 checks both results.

Work through GCF and LCM

Questions about 989

What are the factors of 989?

The positive factors are 1, 23, 43, 989. There are 4 factors, including 1 and 989.

Is 989 a prime number?

No. 989 is composite: 23 × 43 = 989.

How do you write 989 in Roman numerals?

989 is CMLXXXIX in standard subtractive Roman numeral notation.

What is the binary representation of 989?

989 in decimal is 1111011101 in base 2. Adding its active place values gives 512 + 256 + 128 + 64 + 16 + 8 + 4 + 1 = 989.

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 989

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

The digits of 989 add to 26. 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.