Number of the day: 28920

Properties of the number 28920:

28920 = 2³ × 3 × 5 × 241 is the 25772^th composite number and is not squarefree.
28920 has 4 distinct prime factors, 32 divisors, 9 antidivisors and 7680 totatives.
28920 has a semiprime digit sum 21 in base 10.
28920 has a Fibonacci digit sum 21 in base 10.
28920 has a triangular digit sum 21 in base 10.
28920 = (81 × 82)/2 + … + (88 × 89)/2 = (71 × 72)/2 + … + (80 × 81)/2 is the sum of at least 2 consecutive triangular numbers in 2 ways.
28920 = 7231² - 7229² = 3617² - 3613² = 2413² - 2407² = 1451² - 1441² = 1211² - 1199² = 733² - 713² = 497² - 467² = 271² - 211² is the difference of 2 nonnegative squares in 8 ways.
28920 = (240 × 241)/2 is a triangular number.
28920 is the difference of 2 positive pentagonal numbers in 2 ways.
28920 = 2² + 4² + 170² is the sum of 3 positive squares.
28920² = 14400² + 25080² = 3528² + 28704² = 11424² + 26568² = 17352² + 23136² is the sum of 2 positive squares in 4 ways.
28920² is the sum of 3 positive squares.
28920 is a divisor of 659⁴ - 1.
28920 is palindromic in (at least) base 14.
28920 in base 14 = a77a and consists of only the digits '7' and 'a'.
28920 in base 15 = 8880 and consists of only the digits '0' and '8'.
28920 in base 19 = 4422 and consists of only the digits '2' and '4'.
28920 in base 42 = GGO and consists of only the digits 'G' and 'O'.

The number 28920 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A000385: Convolution of A000203 with itself.
A068131: Triangular numbers with sum of digits = 21.
A082036: (9*n^2+3*n+1)*n!.
A082038: A square array of quadratic-factorial numbers, read by antidiagonals.
A110450: a(n) = n*(n+1)*(n^2+n+1)/2.
A124494: Numbers n for which 2n-1, 4n-1, 8n-1 and 16n-1 are primes.
A222716: Numbers which are both the sum of n+1 consecutive triangular numbers and the sum of the n-1 immediately following triangular numbers.
A253651: Triangular numbers that are the product of a triangular number and a prime number.
A257712: Triangular numbers (A000217) that are the sum of eight consecutive triangular numbers.
A257713: Triangular numbers (A000217) that are the sum of ten consecutive triangular numbers.