## Gerolamo Cardano was born on this day 515 years ago.

### Properties of the number 28470:

28470 = 2 × 3 × 5 × 13 × 73 is the 25372^{th}composite number and is squarefree.

28470 has 5 distinct prime factors, 32 divisors, 17 antidivisors and 6912 totatives.

28470 has a semiprime digit sum 21 in base 10.

28470 has a Fibonacci digit sum 21 in base 10.

28470 has a triangular digit sum 21 in base 10.

28470 = (75 × 76)/2 + … + (83 × 84)/2 is the sum of at least 2 consecutive triangular numbers in 1 way.

28470 is the difference of 2 positive pentagonal numbers in 3 ways.

28470 = 26

^{2}+ 35

^{2}+ 163

^{2}is the sum of 3 positive squares.

28470

^{2}= 18720

^{2}+ 21450

^{2}= 9030

^{2}+ 27000

^{2}= 12600

^{2}+ 25530

^{2}= 8976

^{2}+ 27018

^{2}= 2106

^{2}+ 28392

^{2}= 12864

^{2}+ 25398

^{2}= 5928

^{2}+ 27846

^{2}= 5238

^{2}+ 27984

^{2}= 16182

^{2}+ 23424

^{2}= 17082

^{2}+ 22776

^{2}= 7008

^{2}+ 27594

^{2}= 14454

^{2}+ 24528

^{2}= 10950

^{2}+ 26280

^{2}is the sum of 2 positive squares in 13 ways.

28470

^{2}is the sum of 3 positive squares.

28470 is a divisor of 1487

^{4}- 1.

28470 is palindromic in (at least) the following bases: 41, and -86.

28470 in base 3 = 1110001110 and consists of only the digits '0' and '1'.

28470 in base 27 = 1c1c and consists of only the digits '1' and 'c'.

28470 in base 41 = GcG and consists of only the digits 'G' and 'c'.

### The number 28470 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.A062254: 3rd level triangle related to Eulerian numbers and binomial transforms (A062253 is second level, triangle of Eulerian numbers is first level and triangle with Z(0,0)=1 and Z(n,k)=0 otherwise is 0th level).

A133409: Zero followed by partial sums of A133405.

A217020: Eulerian numbers of the third order.

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