Number of the day: 7440

Properties of the number 7440:

7440 = 2⁴ × 3 × 5 × 31 is the 6497^th composite number and is not squarefree.
7440 has 4 distinct prime factors, 40 divisors, 9 antidivisors and 1920 totatives.
7440 has an emirpimes digit sum 15 in base 10.
7440 has a triangular digit sum 15 in base 10.
7440 is the difference of 2 nonnegative squares in 12 ways.
7440 is the sum of 2 positive triangular numbers.
7440 is the difference of 2 positive pentagonal numbers in 1 way.
7440 = 40² + 52² + 56² is the sum of 3 positive squares.
7440² = 4464² + 5952² is the sum of 2 positive squares in 1 way.
7440² is the sum of 3 positive squares.
7440 is a divisor of 311² - 1.
7440 is palindromic in (at least) base 92.
7440 in base 19 = 11bb and consists of only the digits '1' and 'b'.
7440 in base 30 = 880 and consists of only the digits '0' and '8'.
7440 in base 38 = 55U and consists of only the digits '5' and 'U'.
7440 in base 43 = 411 and consists of only the digits '1' and '4'.

The number 7440 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A002875: Sorting numbers (see Motzkin article for details).
A024365: Areas of right triangles with co-prime integer sides.
A024406: Ordered areas of primitive Pythagorean triangles.
A032563: Numbers n such that A102489(n) is divisible by n.
A035008: Total number of possible knight moves on an (n+2) X (n+2) chessboard, if the knight is placed anywhere.
A054567: a(n) = 4*n^2 - 7*n + 4.
A055112: a(n) = n*(n+1)*(2*n+1).
A055522: Largest area of a Pythagorean triangle with n as length of one of the three sides (in fact as a leg).
A179693: Products of 4 distinct primes (p^4*q*r*s).
A269619: T(n,k)=Number of length-n 0..k arrays with no repeated value differing from the previous repeated value by other than plus two, zero or minus 1.