13149
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19520
- Proper Divisor Sum (Aliquot Sum)
- 6371
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8748
- Möbius Function
- 0
- Radical
- 1461
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 76
- 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
- Numbers k that divide s(k), where s(1)=1, s(j)=19*s(j-1)+j.at n=22A014869
- Numbers k such that k | 5^k + 1.at n=42A015951
- Number of days in n years (n=4 is the first leap year).at n=35A033171
- Number of days in n years (n=3 is the first leap year).at n=35A033172
- Number of days in n years (n=2 is the first leap year).at n=35A033173
- Number of days in n years (n=1 is the first leap year).at n=35A033174
- Numbers n such that phi(phi(n)) + sigma(sigma(n)) - phi(sigma(n)) - sigma(phi(n)) = sigma(n).at n=3A066946
- Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 1100-0100-0111-0001 pattern in any orientation.at n=11A147200
- Numbers k which divide the periodic part of the decimal expansion of 1/k.at n=5A171928
- Numbers n which divide the periodic part (with zeros at end) of the decimal expansion of 1/n.at n=12A179267
- Numbers k>1 such that 10^phi(k) == 1 (mod k^2), where phi(n)=A000010(n).at n=4A241977
- Number of (n+1) X (6+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=3A250753
- T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=39A250755
- Number of (4+1) X (n+1) 0..2 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing x(i,j)+x(i-1,j) in the j direction.at n=5A250759
- Partial sums of A299900.at n=29A299901
- Numbers k such that A307437(k) is divisible by 3.at n=19A342037