Number of the day: 42049

Properties of the number 42049:

42049 = 7 × 6007 is semiprime and squarefree.
42049 has 2 distinct prime factors, 4 divisors, 15 antidivisors and 36036 totatives.
42049 has a prime digit sum 19 in base 10.
42049 = 1³ + 14³ + 34³ is the sum of 3 positive cubes in 1 way.
42049 = 21025² - 21024² = 3007² - 3000² is the difference of 2 nonnegative squares in 2 ways.
42049 is the sum of 2 positive triangular numbers.
42049 is the difference of 2 positive pentagonal numbers in 2 ways.
42049 = 12² + 17² + 204² is the sum of 3 positive squares.
42049² is the sum of 3 positive squares.
42049 is a proper divisor of 97²² - 1.
42049 = '4' + '2049' is the concatenation of 2 semiprime numbers.
42049 is an emirpimes in (at least) the following bases: 5, 11, 12, 14, 21, 23, 26, 28, 31, 38, 40, 46, 47, 54, 55, 56, 60, 61, 63, 65, 66, 67, 71, 73, 82, 83, 88, 89, 94, 95, and 99.
42049 is palindromic in (at least) the following bases: 77, -78, and -92.
42049 in base 17 = 8988 and consists of only the digits '8' and '9'.

The number 42049 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A008779: Number of n-dimensional partitions of 5.
A041266: Numerators of continued fraction convergents to sqrt(146).
A042118: Numerators of continued fraction convergents to sqrt(584).
A150579: Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (0, 0, 1), (0, 1, 1), (1, -1, 1), (1, 0, -1)}
A154515: a(n) = 648*n^2 + 72*n + 1.
A157326: a(n) = 10368*n^2 + 288*n + 1.
A157337: a(n) = 128*n^2 + 32*n + 1.
A157433: 128n^2 + 2336n + 10657.
A157919: a(n) = 50*n^2 - 1.
A306973: Numerator of best rational approximation x/y of sqrt(k), y<=k, with k given by A306972. The corresponding denominators are given in A306974.