399

Names of 399

• Cardinal: 399 can be written as Three hundred ninety-nine.

Scientific notation

• Scientific notation: 3.99 × 10²

Factors of 399

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 3
• Sum of prime factors: 29

Divisors of 399

• Number of divisors d(n): 8
• Complete list of divisors:
  1 3 7 19 21 57 133 399
• Sum of all divisors σ(n): 640
• Sum of proper divisors (its aliquot sum) s(n): 241
• 399 is a deficient number, because the sum of its proper divisors (241) is less than itself. Its deficiency is 158

Bases of 399

• Binary: 110001111₂
• Hexadecimal: 0x18F
• Base-36: B3

Squares and roots of 399

• 399 squared (399²) is 159201
• 399 cubed (399³) is 63521199
• The square root of 399 is 19.9749843553
• The cube root of 399 is 7.3619178209

Scales and comparisons

• 399 seconds is equal to 6 minutes, 39 seconds.
• To count from 1 to 399 would take you about three minutes.

  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 399 cubic inches would be around 0.6 feet tall.

Recreational maths with 399

• 399 backwards is 993
• 399 is a Harshad number.
• The number of decimal digits it has is: 3
• The sum of 399's digits is 21
• More coming soon!