21855

Names of 21855

• Cardinal: 21855 can be written as Twenty-one thousand, eight hundred fifty-five.

Scientific notation

• Scientific notation: 2.1855 × 10⁴

Factors of 21855

• Number of distinct prime factors ω(n): 4
• Total number of prime factors Ω(n): 4
• Sum of prime factors: 86

Divisors of 21855

• Number of divisors d(n): 16
• Complete list of divisors:
  1 3 5 15 31 47 93 141 155 235 465 705 1457 4371 7285 21855
• Sum of all divisors σ(n): 36864
• Sum of proper divisors (its aliquot sum) s(n): 15009
• 21855 is a deficient number, because the sum of its proper divisors (15009) is less than itself. Its deficiency is 6846

Bases of 21855

• Binary: 101010101011111₂
• Hexadecimal: 0x555F
• Base-36: GV3

Squares and roots of 21855

• 21855 squared (21855²) is 477641025
• 21855 cubed (21855³) is 10438844601375
• The square root of 21855 is 147.8343667757
• The cube root of 21855 is 27.9586976089

Scales and comparisons

• 21,855 seconds is equal to 6 hours, 4 minutes, 15 seconds.
• To count from 1 to 21,855 would take you about six hours.

  This is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)

• A cube with a volume of 21855 cubic inches would be around 2.3 feet tall.

Recreational maths with 21855

• 21855 backwards is 55812
• The number of decimal digits it has is: 5
• The sum of 21855's digits is 21
• More coming soon!