13231
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13464
- Proper Divisor Sum (Aliquot Sum)
- 233
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 13000
- Möbius Function
- 1
- Radical
- 13231
- 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
- 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
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (Fibonacci numbers), t = A001950 (upper Wythoff sequence).at n=22A024465
- Palindromic Super-2 Numbers.at n=18A032750
- Number of partitions of n into parts not of the form 19k, 19k+6 or 19k-6. Also number of partitions with at most 5 parts of size 1 and differences between parts at distance 8 are greater than 1.at n=36A035975
- a(n) is the smallest composite number c such that A002110(n) + c is prime.at n=25A038771
- Composite palindromes whose sum of prime factors is palindromic (counted with multiplicity).at n=20A046354
- Odd numbers with only palindromic prime factors whose sum is palindromic (counted with multiplicity).at n=35A046356
- Composite palindromes with only palindromic prime factors whose sum is palindromic (counted with multiplicity).at n=8A046357
- Palindromes with exactly 2 palindromic prime factors (counted with multiplicity), and no other prime factors.at n=24A046376
- Palindromes with exactly 2 distinct palindromic prime factors.at n=20A046408
- Centered 21-gonal numbers.at n=35A069178
- Numbers n for which there are exactly four k such that n = k + reverse(k).at n=29A072428
- a(n) = (6^n - 5^n - 4^n - 3^n + 4*2^n)/2.at n=6A081679
- Palindromes arising in A082270.at n=26A082271
- Palindromic time display in hours, minutes, seconds on a six spaced 24-hour digital clock, using hours 1-24.at n=32A082567
- Palindromes n such that 4n + 1 is also a palindrome.at n=12A083831
- Palindromic brilliant numbers.at n=11A084350
- a(1) = 2; then smallest palindrome > 1 not occurring earlier such that every partial concatenation is a prime.at n=33A088086
- Number of partitions of n-set into "lists", in which every even list appears an even number of times, cf. A000262.at n=7A102760
- Concatenation of palindrome k and its 10's complement is prime.at n=34A108537
- a(1) = 11. a(n) is obtained by filling the space between neighboring digits in a(n-1) with their sum.at n=2A110398