21209138405

Names of 21209138405

• Cardinal: 21209138405 can be written as Twenty-one billion, two hundred nine million, one hundred thirty-eight thousand, four hundred five.

Scientific notation

• Scientific notation: 2.1209138405 × 10¹⁰

Factors of 21209138405

• Number of distinct prime factors ω(n): 5
• Total number of prime factors Ω(n): 5
• Sum of prime factors: 1503717

Divisors of 21209138405

• Number of divisors d(n): 32
• Complete list of divisors:
  1 5 7 13 31 35 65 91 155 217 403 455 1085 2015 2821 14105 1503661 7518305 10525627 19547593 46613491 52628135 97737965 136833151 233067455 326294437 605975383 684165755 1631472185 3029876915 4241827681 21209138405
• Sum of all divisors σ(n): 32334747648
• Sum of proper divisors (its aliquot sum) s(n): 11125609243
• 21209138405 is a deficient number, because the sum of its proper divisors (11125609243) is less than itself. Its deficiency is 10083529162

Bases of 21209138405

• Binary: 10011110000001010011100010011100101₂
• Hexadecimal: 0x4F029C4E5
• Base-36: 9QRDFXH

Squares and roots of 21209138405

• 21209138405 squared (21209138405²) is 449827551882445944025
• 21209138405 cubed (21209138405³) is 9540454806257114316757107780125
• The square root of 21209138405 is 145633.5758161559
• The cube root of 21209138405 is 2768.0526223697

Scales and comparisons

• 21,209,138,405 seconds is equal to 674 years, 20 weeks, 3 hours, 20 minutes, 5 seconds.
• To count from 1 to 21,209,138,405 would take you about one thousand, three hundred forty-eight years!

  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 21209138405 cubic inches would be around 230.7 feet tall.

Recreational maths with 21209138405

• 21209138405 backwards is 50483190212
• 21209138405 is a Harshad number.
• The number of decimal digits it has is: 11
• The sum of 21209138405's digits is 35
• More coming soon!