2的幂

2的幂是指符合型式,而也是整數的數,也就是底數2指數為整數 n

從1到1024(20 至 210

在有些情形下,會將限制在正整數及零的範圍內[1],因此2的幂包括1、2以及2自乘多次的乘積[2]

因為2是二進制的底數,因此在常出現二進制的電腦科學中,2的幂也很常見。若將2的幂用二進制表示,會是100…000、0.00…001或是1的形式,類似用十進制表示10的幂的情形。

表示方法

  • 2 ^ n
  • 2 ** n
  • power(2, n)
  • 2的n次幂
  • 2的n次方

與2的冪有關的數字

  • 比某一个2的幂小1的素数,在数学上称为梅森素数;例如数字3是最小的梅森素数( )。
  • 比某一个2的幂大1的素数,在数学上称为费马素数;如数字3也是最小的费马素数( )。
  • 一个以2的幂为分母的分数称为二进有理数
  • 可以表示为连续正整数和的数称为礼貌数,2的幂不會是礼貌数。

2的幂列表

20=1216=65,536232=4,294,967,296248=281,474,976,710,656
21=2217=131,072233=8,589,934,592249=562,949,953,421,312
22=4218=262,144234=17,179,869,184250=1,125,899,906,842,624
23=8219=524,288235=34,359,738,368251=2,251,799,813,685,248
24=16220=1,048,576236=68,719,476,736252=4,503,599,627,370,496
25=32221=2,097,152237=137,438,953,472253=9,007,199,254,740,992
26=64222=4,194,304238=274,877,906,944254=18,014,398,509,481,984
27=128223=8,388,608239=549,755,813,888255=36,028,797,018,963,968
28=256224=16,777,216240=1,099,511,627,776256=72,057,594,037,927,936
29=512225=33,554,432241=2,199,023,255,552257=144,115,188,075,855,872
210=1,024226=67,108,864242=4,398,046,511,104258=288,230,376,151,711,744
211=2,048227=134,217,728243=8,796,093,022,208259=576,460,752,303,423,488
212=4,096228 =268,435,456244=17,592,186,044,416260=1,152,921,504,606,846,976
213=8,192229=536,870,912245=35,184,372,088,832261=2,305,843,009,213,693,952
214=16,384230=1,073,741,824246=70,368,744,177,664262=4,611,686,018,427,387,904
215=32,768231=2,147,483,648247=140,737,488,355,328263=9,223,372,036,854,775,808

2的2的幂次方列表

220 = 21 = 2
221 =22 = 4
222 =24 = 16
223 =28 = 256
224 =216 = 65,536
225 =232 = 4,294,967,296
226 =264 = 18,446,744,073,709,551,616
227 =2128 = 340,282,366,920,938,463,463,374,607,431,768,211,456
228 =2256 = 115,792,089,237,316,195,423,570,985,008,687,907,853,269,984,665,640,564,039,457,584,007,913,129,639,936

參考資料

相關條目