13427
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13920
- Proper Divisor Sum (Aliquot Sum)
- 493
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12936
- Möbius Function
- 1
- Radical
- 13427
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 138
- 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)=a(n-1)+a(n-4).at n=29A014098
- Pseudoprimes to base 51.at n=41A020179
- Strong pseudoprimes to base 51.at n=12A020277
- Shifts left 2 places under "DGK" (bracelet, element, unlabeled) transform.at n=20A032237
- Numbers k such that Euler phi(k) / Carmichael lambda(k) = 14.at n=28A066696
- Nonprimes k such that k divides 3^(k-1) - 2^(k-1).at n=29A073631
- a(n) = (n+1)*prime(n) + n*prime(n+1).at n=38A097240
- Semiprimes k=p*q such that the polynomial (1+x)^k (mod k) has p+q nonzero terms.at n=43A116926
- 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, -1, 0), (0, 0, 1), (0, 1, 0), (1, 1, 1)}.at n=7A151090
- a(n) = 16*n^2 - n.at n=28A157446
- a(n) = 841*n^2 - 29.at n=3A158667
- Number of distinct sets of nonnegative integers with perimeter n, as defined in the comments.at n=46A182372
- Difference between the number of primes with n digits (A006879) and the difference of consecutive integers nearest to Riemann(10^n) (see A228113).at n=13A228114
- a(n) = floor((10*n^3 + 57*n^2 + 102*n + 72) / 72).at n=44A254875
- a(n) = n*(n^2 + 3*n - 2)/2.at n=29A256857
- 35-gonal numbers: a(n) = n*(33*n-31)/2.at n=29A282851
- Numbers k such that 3^(k-1) == 2^(k-1) !== 1 (mod k).at n=20A285300
- a(n) = Sum_{k=3..n} binomial(k-1,2) * floor(n/k).at n=41A366970