15949
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16380
- Proper Divisor Sum (Aliquot Sum)
- 431
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15520
- Möbius Function
- 1
- Radical
- 15949
- Omega Function (Ω)
- 2
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 53
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- Squarefree Number
- yes
- 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) = n*(19*n - 1)/2.at n=41A022276
- Self-convolution of natural numbers >= 3.at n=40A023551
- Denominators of continued fraction convergents to sqrt(314).at n=12A041593
- Numbers k such that 7*2^k + 3 is prime.at n=18A058592
- Triangle read by rows: T(n,k) is the number of deco polyominoes of height n such that the bottom of the last column is at level k (n>=1; k>=0). A deco polyomino is a directed column-convex polyomino in which the height, measured along the diagonal, is attained only in the last column.at n=23A121632
- Indices k such that 9 plus the k-th triangular number is a perfect square.at n=10A154142
- Members of A038512 of the form k, k+2, k+6, k+8.at n=19A155511
- a(n) = 2^(floor((n-1)/2)) - n*(n-1)/2.at n=29A163417
- Numbers k such that 7*R_k - 30 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=15A256829
- Molien series for invariants of finite Coxeter group D_10 (bisected).at n=37A266773
- Essential dimension of the spin group Spin_n over an algebraically closed field of characteristic different from 2.at n=25A280191
- E.g.f. A(x) satisfies A(x) = exp(x*A(-3*x)).at n=4A385529
- Number of connected dominating sets in the n-Cameron graph.at n=2A387373