13731
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 19200
- Proper Divisor Sum (Aliquot Sum)
- 5469
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8712
- Möbius Function
- -1
- Radical
- 13731
- 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
- 151
- 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
- Palindromic Super-2 Numbers.at n=23A032750
- Numbers whose base-5 representation contains exactly three 1's and three 4's.at n=15A045262
- a(n) = smallest palindrome > a(n-1) such that a(1)*a(2)*...*a(n) + 1 is prime with a(1) = 2.at n=20A051896
- Smallest palindromic multiple of n-th prime.at n=45A062888
- Number of length 3 walks on an n-dimensional hypercubic lattice starting at the origin and staying in the nonnegative part.at n=23A064043
- Palindromic odd composite numbers that are the products of an odd number of distinct primes.at n=29A075808
- Palindromes n such that 10n01 is a prime.at n=22A099744
- Palindromic primes in base 9 (written in base 9).at n=22A117703
- Binomial transform of Bessel numbers A006789.at n=8A153197
- Convolution triangle by rows, T(n,k) = A153197(n-k) * A153198.at n=45A153206
- a(n) = (2*n^3 + 5*n^2 + 21*n)/2.at n=22A162266
- G.f. A(x) satisfies A(x) = 1/(1 - x*A(2*x)^5).at n=4A171195
- Number of 0..23 integer arrays v[1..n] of length n with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..n-1.at n=2A171329
- Number of 0..n-1 integer arrays v[1..3] of length 3 with all autocorrelation values sum(i){v[i]*v[i-k]} distinct for k in 0..2.at n=23A171354
- Palindromic mountain numbers.at n=19A173070
- Smallest palindrome beginning with n-th prime.at n=32A185267
- Base-4 analog of A208059.at n=20A212993
- Number of surviving (but not bifurcating) nodes at generation n in the binary tree of persistently squarefree numbers (see A293230).at n=33A293521
- Expansion of Product_{k>=1} 1/(1 - x^k)^(mod(k,3)).at n=32A301589
- G.f. A(x) = Sum_{n>=0} x^n*(A(x)^n - 1)^n/(1 - x*A(x)^n)^(n+1).at n=8A324618