21280

Names of 21280

• Cardinal: 21280 can be written as Twenty-one thousand, two hundred eighty.

Scientific notation

• Scientific notation: 2.128 × 10⁴

Factors of 21280

• Number of distinct prime factors ω(n): 4
• Total number of prime factors Ω(n): 8
• Sum of prime factors: 33

Divisors of 21280

• Number of divisors d(n): 48
• Complete list of divisors:
  1 2 4 5 7 8 10 14 16 19 20 28 32 35 38 40 56 70 76 80 95 112 133 140 152 160 190 224 266 280 304 380 532 560 608 665 760 1064 1120 1330 1520 2128 2660 3040 4256 5320 10640 21280
• Sum of all divisors σ(n): 60480
• Sum of proper divisors (its aliquot sum) s(n): 39200
• 21280 is an abundant number, because the sum of its proper divisors (39200) is greater than itself. Its abundance is 17920

Bases of 21280

• Binary: 101001100100000₂
• Hexadecimal: 0x5320
• Base-36: GF4

Squares and roots of 21280

• 21280 squared (21280²) is 452838400
• 21280 cubed (21280³) is 9636401152000
• The square root of 21280 is 145.8766602305
• The cube root of 21280 is 27.7113196447

Scales and comparisons

• 21,280 seconds is equal to 5 hours, 54 minutes, 40 seconds.
• To count from 1 to 21,280 would take you about five 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 21280 cubic inches would be around 2.3 feet tall.

Recreational maths with 21280

• 21280 backwards is 08212
• The number of decimal digits it has is: 5
• The sum of 21280's digits is 13
• More coming soon!