• 10 can be written using four 4's:
• H. Harborth proved that, given 10 points in general position, there are always five of them which are the corners of a convex pentagon that does not contain any of the remaining points.
• Marion's theorem states that the area of the central hexagon determined by trisecting each side of a triangle and connecting the points as shown below, is 1/10 of the area of the triangle.
It is a happy number.
10 is nontrivially palindromic in base 3, base 4 and base 9.
10 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
10 is an esthetic number in base 2, base 3, base 8 and base 10, because in such bases its adjacent digits differ by 1.
It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1 = 7883958449819444595 ⋅7733349.
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
10 is an idoneal number.
10 is an undulating number in base 2 and base 3.
It is the 8-th Perrin number.
10 is a nontrivial repdigit in base 4 and base 9.
It is a plaindrome in base 4, base 6, base 7, base 8 and base 9.
It is a nialpdrome in base 4, base 5, base 9 and base 10.
It is a zygodrome in base 4 and base 9.
It is a panconsummate number.
It is the 3-rd tetrahedral number.
A polygon with 10 sides can be constructed with ruler and compass.
10 is an equidigital number, since it uses as much as digits as its factorization.
10 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 7.
The square root of 10 is about 3.1622776602. The cubic root of 10 is about 2.1544346900.