On this Wikipedia the 7 day apple cider vinegar diet links are at the top of the page across from the article title. This article is about the number. For the year, see AD 7. It is the only prime number preceding a cube.

In English, it is the first natural number whose pronunciation contains more than one syllable. The western Ghubar Arabs’ main contribution was to make the longer line diagonal rather than straight, though they showed some tendencies to making the digit more rectilinear. The line through the middle is useful to clearly differentiate the digit from the digit one, as the two can appear similar when written in certain styles of handwriting. Mersenne prime since the exponent, 3, is itself a Mersenne prime. Leyland prime of the second kind and the fourth Heegner number.

Seven is the lowest natural number that cannot be represented as the sum of the squares of three integers. Seven is the aliquot sum of one number, the cubic number 8 and is the base of the 7-aliquot tree. 7 is the only dimension, besides the familiar 3, in which a vector cross product can be defined. 7 is the lowest dimension of a known exotic sphere, although there may exist as yet unknown exotic smooth structures on the 4-dimensional sphere.

A seven-sided shape is a heptagon. 6 can be constructed by compass and straightedge alone, which makes the heptagon the first regular polygon that cannot be directly constructed with these simple tools. A heptagon in Euclidean space is unable to generate uniform tilings alongside other polygons, like the regular pentagon. There are seven fundamental types of catastrophes. The opposite sides of a standard six-sided dice always add to 7. The Millennium Prize Problems are seven problems in mathematics that were stated by the Clay Mathematics Institute in 2000.

999,999 divided by 7 is exactly 142,857. In fact, if one sorts the digits in the number 142,857 in ascending order, 124578, it is possible to know from which of the digits the decimal part of the number is going to begin with. The remainder of dividing any number by 7 will give the position in the sequence 124578 that the decimal part of the resulting number will start. 5 is the remainder, and would correspond to number 7 in the ranking of the ascending sequence. 2, and this corresponds to number 2 in the sequence. Seven, plus or minus two as a model of working memory. Seven psychological types called the Seven Rays in the teachings of Alice A.