Number of the day: 22009

Properties of the number 22009:

22009 is a cyclic number.
22009 = 13 × 1693 is semiprime and squarefree.
22009 has 2 distinct prime factors, 4 divisors, 13 antidivisors and 20304 totatives.
22009 has an emirp digit sum 13 in base 10.
22009 has a Fibonacci digit sum 13 in base 10.
22009 = 11005² - 11004² = 853² - 840² is the difference of 2 nonnegative squares in 2 ways.
22009 is the sum of 2 positive triangular numbers.
22009 is the difference of 2 positive pentagonal numbers in 2 ways.
22009 = 75² + 128² = 20² + 147² is the sum of 2 positive squares in 2 ways.
22009 = 7² + 78² + 126² is the sum of 3 positive squares.
22009² = 8465² + 20316² = 5880² + 21209² = 10759² + 19200² = 13585² + 17316² is the sum of 2 positive squares in 4 ways.
22009² is the sum of 3 positive squares.
22009 is a proper divisor of 433⁶ - 1.
22009 is an emirpimes in (at least) the following bases: 2, 3, 4, 6, 7, 8, 9, 13, 15, 16, 17, 20, 23, 27, 28, 29, 31, 32, 33, 34, 37, 39, 40, 45, 46, 51, 56, 57, 67, 71, 73, 80, 82, 84, 85, 89, 95, 97, and 98.
22009 is palindromic in (at least) the following bases: -29, -50, and -57.
22009 in base 7 = 121111 and consists of only the digits '1' and '2'.
22009 in base 49 = 988 and consists of only the digits '8' and '9'.
22009 in base 56 = 711 and consists of only the digits '1' and '7'.
22009 in base 60 = 66n and consists of only the digits '6' and 'n'.

The number 22009 belongs to the following On-Line Encyclopedia of Integer Sequences (OEIS) sequences (among others):

Sequence numbers and descriptions below are taken from OEIS.
A077416: Chebyshev S-sequence with Diophantine property.
A088669: Number of partitions of n into decimal repdigit numbers.
A091580: Number of partitions of n into decimal palindromes.
A099505: A transform of the Fibonacci numbers.
A120760: a(1) = a(2) = 1. a(n) = a(n-1) + (largest nonprime {1 or composite} among the first n-2 terms of the sequence).
A135859: Row sums of triangle A135858.
A151792: Partial sums of A151791.
A200669: Number of 0..n arrays x(0..4) of 5 elements with each no smaller than the sum of its three previous neighbors modulo (n+1)
A288605: Position of first appearance of each integer in A088568 (number of 1's minus number of 2's in first n terms of A000002).
A297740: The number of distinct positions on an infinite chess board reachable by the (2,3)-leaper in <= n moves.