15631
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 20520
- Proper Divisor Sum (Aliquot Sum)
- 4889
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11760
- Möbius Function
- 0
- Radical
- 2233
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- no
- Narcissistic Number
- no
- Collatz Steps
- 133
- 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) = ceiling(n*phi^13), where phi is the golden ratio, A001622.at n=30A004968
- 12-gonal (or dodecagonal) pyramidal numbers: a(n) = n*(n+1)*(10*n-7)/6.at n=21A007587
- a(n) = n OR n^3 (applied to ternary expansions).at n=24A008469
- Expansion of 1/((1-x) * (1-5*x) * (1-9*x)).at n=4A016234
- "AFK" (ordered, size, unlabeled) transform of 1,3,5,7,...at n=12A032008
- Sums of 3 distinct powers of 5.at n=20A038475
- Numbers n such that sum of squares of even digits of n equals sum of squares of odd digits of n.at n=22A076164
- a(n) = n^3 + 6.at n=25A084382
- a(n) = n^5 - n^2*(n^2 - 1)/2.at n=7A100242
- Indices of primes in sequence defined by A(0) = 53, A(n) = 10*A(n-1) + 33 for n > 0.at n=17A101582
- a(n) = 5^n + n.at n=6A104745
- Triangle read by rows: T(n,k) is the number of hill-free Dyck paths of semilength n and having k UUDD's, where U=(1,1) and D=(1,-1) (0<=k<=floor(n/2), n>=2). A hill in a Dyck path is a peak at level 1.at n=51A105640
- Number of inequivalent Krom functions on n variables (or 2SAT instances) under permuting and complementing variables.at n=7A109459
- Triangle T(n, m) = T(n-1, m-1) + (4m-3)*T(n-1, m) read by rows 1<=m<=n.at n=23A111578
- Trajectory of 8 under iteration of the map k -> A087712(k).at n=19A144813
- Number of 5-bead necklaces labeled with numbers -n..n not allowing reversal, with sum zero.at n=8A208599
- Numbers of the form 5^j + 6^k, for j and k >= 0.at n=37A226814
- Smallest positive multiple of n whose base-5 representation contains only 0's and 1's.at n=28A244956
- Smallest positive multiple of n whose base-5 representation contains only 0's and 1's.at n=48A244956
- Total area below all lattice paths from (0,0) to (n,0) that do not go below the x-axis or above the diagonal x=y and consist of steps u=(1,1), U=(1,3), H=(1,0), d=(1,-1) and D=(1,-3).at n=8A247748