A list whose items are numbered, with various styles including Arabic numerals and Roman numerals.

plural of vanity number

(mathematics, number theory) A number equal to the number of dots in a geometric figure formed of dots. The series begins with unity and is formed so that subtracting each from the following, and treating the series so formed in the same way, by a continuation of the process, yields equal differences.

(mathematics) Any of the large semiprime numbers to be factored in the RSA Factoring Challenge, a competition from 1991 to 2007 encouraging research into computational number theory.

plural of RSA number

plural of phone number

plural of imaginary number

plural of wrong number

(mathematics) A non-negative integer, the representation of whose square in its base can be split into two parts that add up to itself (such as 297, whose square, 88209, can be split into 88 and 209, totalling 297).

(UK, New Zealand) A telephone number beginning with 0800; these numbers are free for the caller because the call is paid for by the company or organisation being called.