Number of the day: 6426

Properties of the number 6426:

6426 = 2 × 3³ × 7 × 17 is the 5590^th composite number and is not squarefree.
6426 has 4 distinct prime factors, 32 divisors, 17 antidivisors and 1728 totatives.
6426 is the sum of 2 positive triangular numbers.
6426 is the difference of 2 positive pentagonal numbers in 1 way.
6426 = 16² + 29² + 73² is the sum of 3 positive squares.
6426² = 3024² + 5670² is the sum of 2 positive squares in 1 way.
6426² is the sum of 3 positive squares.
6426 is a proper divisor of 613³ - 1.
6426 is palindromic in (at least) the following bases: 38, and -73.
6426 in base 37 = 4PP and consists of only the digits '4' and 'P'.
6426 in base 38 = 4H4 and consists of only the digits '4' and 'H'.
6426 in base 56 = 22g and consists of only the digits '2' and 'g'.

The number 6426 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A014640: Even heptagonal numbers (A000566).
A033571: a(n) = (2*n + 1)*(5*n + 1).
A050047: a(n) = a(n-1)+a(m), where m=2n-2-2^(p+1) and 2^p<n-1<=2^(p+1), for n >= 4.
A073268: Number of plane binary trees whose right (or respectively: left) subtree is a unique "complete" tree of (2^m)-1 nodes with all the leaf-nodes at the same depth m and the left (or respectively: right) subtree is any plane binary tree of size n - 2^m + 1.
A078868: Decimal concatenations of the quadruples (d1,d2,d3,d4) with elements in {2,4,6} for which there exists a prime p >= 5 such that the differences between the 5 consecutive primes starting with p are (d1,d2,d3,d4).
A171256: Numbers n such that sigma(n) = 10*phi(n) (where sigma=A000203, phi=A000010).
A179670: Numbers of the form p^3*q*r*s where p, q, r, and s are distinct primes.
A241647: Numbers m such that the GCD of the x's that satisfy sigma(x)=m is 2.
A277665: 5th-order coefficients of the 1/N-expansion of traces of negative powers of real Wishart matrices with parameter c=2.
A286416: Number T(n,k) of entries in the k-th last blocks of all set partitions of [n]; triangle T(n,k), n>=1, 1<=k<=n, read by rows.