The number 1024 in a treatise on binary numbers by Leibniz (1697)
1024 is the natural number following 1023 and preceding 1025.
1024 is a power of two: 210 (2 to the tenth power).[1] It is the nearest power of two from decimal 1000 and senary 100006 (decimal 1296). It is the 64th quarter square.[2][3]
1024 is the smallest number with exactly 11 divisors (but there are smaller numbers with more than 11 divisors; e.g., 60 has 12 divisors) (sequence A005179 in the OEIS).
Enumeration of groups
The number of groups of order 1024 is 49487367289, up to isomorphism.[4] An earlier calculation gave this number as 49487365422,[5][6] but in 2021 this was shown to be in error.[4]
This count is more than 99% of all the isomorphism classes of groups of order less than 2000.[7]
Approximation to 1000
The neat coincidence that 210 is nearly equal to 103 provides the basis of a technique of estimating larger powers of 2 in decimal notation. Using 210a+b ≈ 2b103a(or 2a≈2a mod 1010floor(a/10) if "a" stands for the whole power) is fairly accurate for exponents up to about 100. For exponents up to 300, 3a continues to be a good estimate of the number of digits.
For example, 253 ≈ 8×1015. The actual value is closer to 9×1015.
In the case of larger exponents, the relationship becomes increasingly inaccurate, with errors exceeding an order of magnitude for a ≥ 97. For example:
In measuring bytes, 1024 is often used in place of 1000 as the quotients of the units byte, kilobyte, megabyte, etc. In 1999, the IEC coined the term kibibyte for multiples of 1024, with kilobyte being used for multiples of 1000.
1024 is the maximum number of computer memory addresses that can be referenced with ten binary switches. This is the origin of the organization of computer memory into 1024-byte chunks or kibibytes.
In the Rich Text Format (RTF), language code 1024 indicates the text is not in any language and should be skipped over when proofing. Most used languages codes in RTF are integers slightly over 1024.
1024 is the lowest non-system and non-reserved port number in TCP/IP networking. Ports above this number can usually be opened for listening by non-superusers.
^Denis Roegel. (2013). A reconstruction of Bürger's table of quarter-squares (1817) (Research Report). Lyons: HAL. p. 18. S2CID 202132792
^ abBurrell, David (2021-12-08). "On the number of groups of order 1024". Communications in Algebra. 50 (6): 2408–2410. doi:10.1080/00927872.2021.2006680. MR 4413840. S2CID 244772374.
^"Numbers of isomorphism types of finite groups of given order". www.icm.tu-bs.de. Archived from the original on 2019-07-25. Retrieved 2017-04-05.
^Besche, Hans Ulrich; Eick, Bettina; O'Brien, E. A. (2002), "A millennium project: constructing small groups", International Journal of Algebra and Computation, 12 (5): 623–644, doi:10.1142/S0218196702001115, MR 1935567, S2CID 31716675
^Paolo, Aluffi (2009). Algebra: Chapter 0. American Mathematical Society. ISBN 9780821847817.