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A yottabyte is a unit of measurement in computers of approximately one million million million million (American septillion) bytes.

Because of irregularities in definition and usage of the kilobyte, the exact number could be any one of the following:

  1. 1,208,925,819,614,629,174,706,176 bytes - 1024 times 1024 times 1024 times 1024 times 1024 times 1024 times 1024 times 1024, or 280. This is 1024 times a zettabyte. This is the definition used in computer science and computer programming
  2. 1,000,000,000,000,000,000,000,000 bytes - or 10 24.
See integral data type.

A yottabyte (280 bytes) is about 2.01 moles of bytes.

A nonabyte is 1024 times a yottabyte

To clarify the meaning(1) above, the International Electrotechnical Commission (IEC), a standards body, in 1997 proposed short unions of the International System of Units (SI) prefixes with the word "binary" (see Binary prefix). They did not provide a name for this number, although, it would probably be yobibyte. This naming convention has not been widely accepted.

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