13601
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 16320
- Proper Divisor Sum (Aliquot Sum)
- 2719
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11088
- Möbius Function
- -1
- Radical
- 13601
- Omega Function (Ω)
- 3
- 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
- 45
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- Pell pseudoprimes: odd composite numbers n such that P(n)-Kronecker(2,n) is divisible by n.at n=22A099011
- Triangle read by rows: T(n,k) is the number of skew Dyck paths of semilength n and having k peaks of height >1 (n >= 1; 0 <= k <= n-1).at n=39A128747
- a(n) = prime(2*n^2) - 2*n^2.at n=29A141086
- Number of n X n binary arrays with all ones connected only in a 1000-1111-1000 pattern in any orientation.at n=7A146413
- Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1111-1000 pattern in any orientation.at n=17A146415
- a(n) = 400 * n + 1.at n=33A158313
- a(n) = 34*n^2 + 1.at n=20A158586
- a(n) = 8*n^2 + 20*n + 1.at n=40A161617
- a(n) = 12*n^2 - 8*n + 1.at n=34A185212
- Nonprimes such that it takes exactly 4 iterations of reverse-and-add digits to generate a prime.at n=36A245209
- Triangle read by rows, the numerators of the Bell transform of B(n,1) where B(n,x) are the Bernoulli polynomials.at n=60A265314
- Areas of triangles associated with the Padovan sequence.at n=7A289669
- Number of normal generalized Young tableaux of size n with all rows and columns weakly increasing and all regions connected skew partitions.at n=7A300122
- Composite numbers k such that Pell(k) == 1 (mod k).at n=25A319042
- a(n) is the least exponent k greater than 1 such that prime(n)^k starts and ends in prime(n).at n=33A320775
- Numbers k such that 323*2^k+1 is prime.at n=10A322954
- Odd composite integers m such that A006497(2*m-J(m,13)) == 3*J(m,13) (mod m), where J(m,13) is the Jacobi symbol.at n=37A339518
- Odd composite integers m such that A005248(2*m-J(m,5)) == 3 (mod m), where J(m,5) is the Jacobi symbol.at n=37A339521
- Odd composite integers m such that A000045(2*m-J(m,5)) == 1 (mod m), where J(m,5) is the Jacobi symbol.at n=15A340118
- Numbers k such that sigma(k)^2 is divisible by k-1.at n=23A344347