12521
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 13200
- Proper Divisor Sum (Aliquot Sum)
- 679
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 11844
- Möbius Function
- 1
- Radical
- 12521
- 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
- 63
- 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
- Numbers k such that the continued fraction for sqrt(k) has period 96.at n=32A020435
- Odd palindromes in which parity of digits alternates.at n=37A030148
- Numbers k such that 183*2^k+1 is prime.at n=28A032468
- Numbers k such that k and its reversal are both multiples of 19.at n=34A062907
- Palindromic time display in hours, minutes, seconds on a six spaced 24-hour digital clock, using hours 1-24.at n=25A082567
- Palindromes such that the sum of the digits is prime.at n=46A083393
- Smallest palindrome > 1 and == 1 (mod n-th palindrome).at n=39A083477
- Palindromic numbers with property that sum of digits is prime and number of prime digits is prime.at n=15A093807
- Consider all (2n+1)-digit palindromic primes of the form 30...0M0...03 (so that M is a palindrome with <= 2n-1 digits); a(n) = smallest such M.at n=33A100955
- Number of digits in numbers appearing in A108225.at n=18A109070
- Palindromic primes in base 7 (written in base 7).at n=12A117702
- Palindromic primes in base 9 (written in base 9).at n=20A117703
- Palindromic composites such that some digit permutation is prime.at n=27A119378
- a(n) = 8*n^2 - 7*n + 1.at n=40A125201
- E.g.f. satisfies: A(x) = exp(x*A(((x+1)^6-1)/6)).at n=5A143637
- Numbers divisible by the sum of 4th powers of their digits.at n=37A169665
- Palindromic mountain numbers.at n=11A173070
- a(n) = Sum_{d|n} phi(d^tau(d)).at n=24A179115
- Number of (w,x,y) with all terms in {0,...,n} and |w-x| + |x-y| > w+x+y.at n=23A213482
- Positive palindromes that are not the sum of two positive palindromes.at n=36A213879