13031
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13272
- Proper Divisor Sum (Aliquot Sum)
- 241
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12792
- Möbius Function
- 1
- Radical
- 13031
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 107
- 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
- Octal palindromes which are also primes.at n=22A006341
- [ exp(19/20)*n! ].at n=6A030852
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 23 ones.at n=5A031791
- Palindromic Super-2 Numbers.at n=16A032750
- Smallest palindromic multiple of n-th prime.at n=36A062888
- Numbers n for which there are exactly four k such that n = k + reverse(k).at n=28A072428
- a(1) = 1, a(n) = smallest palindrome not included earlier such that a(1)+...+a(n) is a palindrome.at n=29A073880
- a(n) = floor((n+2)^(n+2)/n^n).at n=41A078111
- Palindromic time display in hours, minutes, seconds on a six spaced 24-hour digital clock, using hours 1-24.at n=30A082567
- Smallest palindromic number relatively prime to all the previous terms.at n=34A083137
- Composite numbers in A083137.at n=5A083138
- Palindromes n such that 4n + 1 is also a palindrome.at n=10A083831
- Palindromes p such that 5p + 1 is also a palindrome.at n=9A083833
- Palindromes n such that 6n + 1 is also a palindrome.at n=9A083835
- Consider all (2n+1)-digit palindromic primes of the form 10...0M0...01 (so that M is a palindrome with <= 2n-1 digits); a(n) = smallest such M.at n=42A100026
- Numbers n such that n and pi(n) (A000720) are palindromic.at n=26A103357
- a(n) = (p-1)! mod p^2 where p = n-th prime.at n=41A112660
- Palindromic primes in base 4 (written in base 4).at n=9A117699
- Palindromes in base 4 (written in base 4).at n=43A118595
- Palindromic composites such that some digit permutation is prime.at n=28A119378