15849
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 23520
- Proper Divisor Sum (Aliquot Sum)
- 7671
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10548
- Möbius Function
- 0
- Radical
- 1761
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 2
Special
- Factorial
- no
- Catalan Number
- no
- Bell Number
- no
- Motzkin Number
- no
- Primorial
- no
Figurate Numbers
- Fibonacci Number
- no
- Triangular Number
- no
- Perfect Square
- no
- Perfect Cube
- no
- Pentagonal Number
- no
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 58
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = floor(10000*log_2(n)).at n=2A004268
- Number of diagonally symmetric polyominoes with n cells.at n=19A006748
- Powers of fifth root of 10 rounded to nearest integer.at n=21A018142
- Powers of fifth root of 10 rounded up.at n=21A018143
- Smallest of 4 consecutive numbers each divisible by a square.at n=26A070284
- Odd numbers k such that the palindromic wing number (a.k.a. near-repdigit palindrome) 7*(10^k - 1)/9 - 2*10^((k-1)/2) is prime.at n=9A077785
- a(n) = (A083108(n) - 1)/n.at n=5A083109
- Triangle read by rows: T(n,k) is the number of Motzkin paths of length n and having k UHD's, where U=(1,1),H=(1,0),D=(1,-1) (0<=k<=floor(n/3)).at n=36A114583
- Expansion of 1/sqrt(1-6x-3x^2).at n=6A122868
- Number of Motzkin paths with no peaks and with level steps at height 0 having three colors except that consecutive level steps at height 0 must have different colors.at n=11A125267
- Smallest number whose tenth power has at least n digits.at n=42A130084
- Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 01010-11111 pattern in any orientation.at n=17A147063
- a(n) = a(n-1) + a(n-2) + a(n-3), with a(0) = 1, a(1) = a(2) = 9.at n=14A214831
- Dziemianczuk's array S(i,j) read by antidiagonals.at n=21A232973
- Numbers k such that k^6 starts with k itself (in base 10).at n=12A233452
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 163", based on the 5-celled von Neumann neighborhood.at n=28A270455
- Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 371", based on the 5-celled von Neumann neighborhood.at n=28A271456
- Numbers n such that the decimal number concat(9,n) is a square.at n=23A273364
- Numbers whose sum of anti-divisors is equal to the sum of its unitary divisors.at n=15A273992
- Solution of the complementary equation a(n) = a(n-1) + a(n-2) + n*b(n-1), where a(0) = 1, a(1) = 2, b(0) = 3, b(1) = 4, and (a(n)) and (b(n)) are increasing complementary sequences.at n=14A296288