International Standard Serial Number International Standard Serial Number An International Standard Serial Number (ISSN) is an eight-digit serial number used to uniquely identify a serial publication. The ISSN is especially helpful in distinguishing between serials with the same title. ISSN are used in ordering, cataloging, interlibrary loans, and other practices in connection with serial literature. The ISSN system was first drafted as an International Organization for Standardization (ISO) international standard in 1971 and published as ISO 3297 in 1975. ISO subcommittee TC 46/SC 9 is responsible for maintaining the standard. When a serial with the same content is published in more than one media
Kaprekar number for base "b" is then one which lies in the set "K"("b"), and a Kaprekar number for base "b" is one which lies in any one of the sets "K"("b"), "K"("b"), "K"("b"),…. 297 is a Kaprekar number for base 10, because 297 = 88209, which can be split into 88 and 209, and 88 + 209 = 297. By convention, the second part may start with the digit 0, but must be nonzero. For example, 999 is a Kaprekar number for base 10, because 999 = 998001, which can be split into 998 and 001, and 998 + 001 =