12541
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 13
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 12542
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 12540
- Möbius Function
- -1
- Radical
- 12541
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1498
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Primes p such that the multiplicative order of 2 modulo p is (p-1)/5.at n=31A001135
- Sextan primes: p = (x^6 + y^6)/(x^2 + y^2).at n=23A002647
- Expansion of g.f. 1/((1-2x)(1-3x)(1-9x)).at n=4A016278
- Primes of form k^2 - 3.at n=20A028874
- Numbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted then there are a pair of central terms both equal to 10.at n=16A031423
- Value of D for incrementally largest values of minimal x satisfying Pell equation x^2-Dy^2=1.at n=34A033316
- Row 4 of square array defined in A047671.at n=10A047673
- Primes with 14 as smallest positive primitive root.at n=8A061327
- Least k such that Sum_{i=1..k} (prime(i) + prime(i+2) - 2*prime(i+1)) = 2n + 1.at n=33A073051
- Number of balanced numbers > 2^(n-1) and <= 2^n.at n=38A078555
- a(n) = a(n-1) + a(n-2) + 2 where a(0) = a(1) = 1.at n=18A111314
- a(1) = 11, a(n) = least k such that concatenation of n copies of k with all previous concatenation gives a prime.at n=34A111477
- Primes which are the sum of a twin prime pair + 1.at n=37A118071
- Primes for which the weight as defined in A117078 is 23.at n=26A119504
- Row sums of A131325.at n=18A131326
- Mountain primes.at n=26A134951
- Mother primes of order 9.at n=36A136068
- Indices where A138554 requires only squares < floor(sqrt(n))^2.at n=38A138555
- Primes of the form x^2 + 1365*y^2.at n=30A139667
- Triangle T(n,k) = 4*binomial(n,k)^2 - 3, read by rows, 0<=k<=n.at n=39A141596