25 (number)

25 (twenty-five) is the natural number following 24 and preceding 26.

In mathematics

It is a square number, being 5² = 5 × 5. It is the smallest square that is also a sum of two (non-zero) squares: 25 = 3² + 4². Hence it often appears in illustrations of the Pythagorean theorem.

25 is a centered octagonal number, a centered square number, and an automorphic number.

25 percent (%) is equal to 1/4.

25 has an aliquot sum of 6 and number 6 is the first (or smallest) number to have an aliquot sequence that does not culminate in 0 through a prime. Twenty-five is the aliquot sum of three integers; 95, 119, and 143. Twenty-five is the second composite member of the 6-aliquot tree.

It is the smallest base 10 Friedman number as it can be expressed by its own numbers: 5².

It is also a Cullen number. 25 is the smallest pseudoprime satisfying the congruence 7ⁿ = 7 mod n.

25 is the smallest aspiring number — a composite non-sociable number whose aliquot sequence does not terminate.

According to the Shapiro inequality, 25 is the least odd integer n such that there exist x₁, x₂, …, x_n such that

King's Own Scottish Borderers

The King's Own Scottish Borderers was a line infantry regiment of the British Army, part of the Scottish Division. On 28 March 2006 the regiment was amalgamated with the Royal Scots, the Royal Highland Fusiliers (Princess Margaret's Own Glasgow and Ayrshire Regiment), the Black Watch (Royal Highland Regiment), the Highlanders (Seaforth, Gordons and Camerons) and the Argyll and Sutherland Highlanders to form the Royal Regiment of Scotland, becoming the 1st Battalion of the new regiment.

History

17th-19th centuries

The regiment was raised on 18 March 1689 by David Melville, 3rd Earl of Leven to defend Edinburgh against the Jacobite forces of James II. It's claimed that 800 men were recruited within the space of two hours. The regiment's first action was at the Battle of Killiecrankie on 27 July 1689. Although this battle was a defeat for the Williamite army, the Jacobite commander, John Graham, 1st Viscount Dundee (Bonnie Dundee), was killed by a volley fired by Leven's Regiment, bringing an end to James II's attempt to save his throne in Scotland. The regiment was judged to have performed well and was granted the privilege of recruiting by beat of drum in the City of Edinburgh without prior permission of the provost.