13421
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 13422
- 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
- 13420
- Möbius Function
- -1
- Radical
- 13421
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 94
- 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
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 1592
- 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=34A001135
- Quintan primes: p = (x^5 + y^5)/(x + y).at n=16A002650
- a(n) = (1 - (-11)^n)/12.at n=4A014993
- Triangle of q-binomial coefficients for q=-11.at n=16A015124
- Triangle of q-binomial coefficients for q=-11.at n=19A015124
- Gaussian binomial coefficient [ n,4 ] for q = -11.at n=1A015300
- a(n) = 10*a(n-1) + 11*a(n-2).at n=5A015592
- Cyclotomic polynomials at x=11.at n=10A019329
- Cyclotomic polynomials at x=-11.at n=5A020510
- Primes that remain prime through 3 iterations of function f(x) = 6x + 1.at n=12A023287
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 58 ones.at n=26A031826
- Lower prime of a difference of 20 between consecutive primes.at n=27A031938
- Primes which when converted to base 36 make single letters or English words.at n=38A038842
- Denominators of continued fraction convergents to sqrt(581).at n=10A042113
- Least prime in A031938 (lesser of primes differing by 20) whose distance to the next 20-twin is 6*n.at n=34A052359
- n consecutive primes differ by 6 or more starting at a(n).at n=15A054693
- n consecutive primes differ by 6 or more starting at a(n).at n=14A054693
- n consecutive primes differ by 6 or more starting at a(n).at n=13A054693
- n consecutive primes differ by 6 or more starting at a(n).at n=12A054693
- n consecutive primes differ by 6 or more starting at a(n).at n=11A054693