13419
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
- 16
- Divisor Sum
- 23040
- Proper Divisor Sum (Aliquot Sum)
- 9621
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7560
- Möbius Function
- 0
- Radical
- 1491
- Omega Function (Ω)
- 5
- 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
- 120
- 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
- Convolution of odd numbers and A000201.at n=28A023658
- a(n+1) = a(n) + a(n-1) + Fibonacci(n), with a(0) = 0 and a(1) = 1.at n=17A029907
- Low-temperature series in u = exp(-4J/kT) for ferromagnetic susceptibility for the spin-1/2 Ising model on hexagonal lattice.at n=10A047709
- a(n) = floor( n^e ), e = 2.718281828...at n=32A061293
- Numbers k such that sopf(k) = sopfr(k+1), where sopf(k) = A008472(k) and sopfr(k) = A001414(k).at n=24A064678
- a(n) = a(n-1) + A000045(n)*a(n-2), a(1) = 1, a(2) = 1.at n=8A135686
- Numbers a(n)=k such that (1/3)*(5*(2k+1)^2-2) is A057080(n)^2.at n=5A145608
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (-1, 1, 1), (1, 0, 0), (1, 1, -1)}.at n=9A148648
- a(n) is the sum of all possible pairs of the first n primes.at n=19A162867
- Shallow diagonal sums of A211226.at n=33A211228
- Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w+4x+4y>0.at n=15A211626
- Number of ordered triples (w,x,y) with all terms in {-n,...-1,1,...,n} and w+5x+5y>0.at n=15A211627
- G.f.: exp( Sum_{n>=1} (2^n - (-1)^n)^n * x^n/n ).at n=4A211898
- Number of partitions of n containing no part i of multiplicity i+1.at n=36A277099
- Numbers k such that 8*10^k + 81 is prime.at n=20A287680
- The number of vertically balanced self-avoiding walks of length n on the upper half-plane of a 2D square lattice where the nodes and connecting rods have equal mass.at n=10A337860
- a(n) = Sum_{d|n} binomial(d+n,n).at n=7A363660