4 (four; /ˈfɔər/) is a number, numeral, and glyph. It is the natural number following 3 and preceding 5. Four is the only number that has the same number of characters as its value in the English language.
Four is the smallest composite number, its proper divisors being 1 and 2. Four is also a highly composite number. The next highly composite number is 6.
Four is the second square number, the second centered triangular number.
4 is the smallest squared prime (p2) and the only even number in this form. It has an aliquot sum of 3 which is itself prime. The aliquot sequence of 4 has 4 members (4, 3, 1, 0) and is accordingly the first member of the 3-aliquot tree.
A number is a multiple of 4 if its last two digits are a multiple of 4. For example, 1092 is a multiple of 4 because 92 = 4 × 23.
Only one number has an aliquot sum of 4 and that is squared prime 9.
The prime factorization of four is two times two.
Four is the smallest composite number that is equal to the sum of its prime factors. (As a consequence of this, it is the smallest Smith number). However, it is the only composite number n for which (n − 1)! ≡ 0 (mod n) is false.
Number 4 is the debut studio album of Ling Tosite Sigure.
Gilbert O'Sullivan (born Raymond Edward O'Sullivan, 1 December 1946) is an Irish singer-songwriter, best known for his early 1970s hits "Alone Again (Naturally)", "Clair" and "Get Down". The music magazine Record Mirror voted him the No. 1 UK male singer of 1972.
Worldwide he has charted 16 top-40 records, including six number one songs, the first of which was 1970's "Nothing Rhymed" (for further information see Gilbert O'Sullivan discography). Such was his popularity in the early 1970s that "Matrimony", an airplay and live favourite from his debut album Himself, remains one of his most famous compositions despite never having been a hit single (except in the Netherlands where it reached No. 4).
His most successful recording period was between 1970 and 1980, though he has since recorded ten studio albums up to 2015. Speaking in 2009 he said, "I write pop songs. End of story. That's all I wanted to do. That's all I want to do. And that's all I continue to want to do. I have no interest in just touring, and living in the past."
Three little maids from school are we
Pert as a school-girl well can be
Filled to the brim with girlish glee
Three little maids from school
Everything is a source of fun
Nobody's safe, for we care for none
Life is a joke that's just begun
Three little maids from school
Three little maids who, all unwary
Come from a ladies' seminary
Freed from its genius tutelary
Three little maids from school
Three little maids from school
One little maid is a bride, Yum-Yum
Two little maids in attendance come
Three little maids is the total sum
Three little maids from school
Three little maids from school
From three little maids take one away
Two little maids remain, and they
Won't have to wait very long, they say
Three little maids from school
Three little maids from school
Three little maids who, all unwary
Come from a ladies' seminary
Freed from its genius tutelary
Three little maids from school