Number of the day: 4078

Properties of the number 4078:

4078 = 2 × 2039 is semiprime and squarefree.
4078 has 2 distinct prime factors, 4 divisors, 9 antidivisors and 2038 totatives.
4078 has a prime digit sum 19 in base 10.
4078 is the difference of 2 positive pentagonal numbers in 2 ways.
4078 = 3² + 10² + 63² is the sum of 3 positive squares.
4078² is the sum of 3 positive squares.
4078 is a proper divisor of 3¹⁰¹⁹ - 1.
4078 is an emirpimes in (at least) the following bases: 2, 4, 5, 6, 8, 11, 15, 25, 28, 29, 37, 39, 41, 44, 45, 51, 52, 54, 56, 58, 59, 62, 64, 66, 67, 69, 70, 71, 86, 87, 89, 91, 94, 95, and 98.
4078 is palindromic in (at least) the following bases: 22, 23, -6, -17, and -19.
4078 in base 4 = 333232 and consists of only the digits '2' and '3'.
4078 in base 16 = fee and consists of only the digits 'e' and 'f'.
4078 in base 18 = caa and consists of only the digits 'a' and 'c'.
4078 in base 22 = 898 and consists of only the digits '8' and '9'.
4078 in base 23 = 7g7 and consists of only the digits '7' and 'g'.
4078 in base 28 = 55i and consists of only the digits '5' and 'i'.

The number 4078 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A064092: Generalized Catalan numbers C(9; n).
A085146: Numbers n such that n!!!!+1 is prime.
A096373: Number of partitions of n such that the least part occurs exactly twice.
A121330: Number of bridged bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition).
A196590: T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,2,0,1,4 for x=0,1,2,3,4
A196802: T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 3,2,0,4,1 for x=0,1,2,3,4
A226441: T(n,k)=Number of permutations of 1..n with fewer than k interior elements having values lying between the values of their neighbors
A239470: Number of 4-separable partitions of n; see Comments.
A254204: T(n,k)=Number of length n 1..(k+2) arrays with no leading or trailing partial sum equal to a prime
A256708: Numbers n such that the decimal expansions of both n and n^2 have 0 as smallest digit and 8 as largest digit.