8431
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 8432
- Proper Divisor Sum (Aliquot Sum)
- 1
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8430
- Möbius Function
- -1
- Radical
- 8431
- 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
- 96
- 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
- 1055
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Quintan primes: p = (x^5 - y^5)/(x - y).at n=8A002649
- Expansion of 1/((1-2*x)*(1-9*x)).at n=4A016133
- Primes that remain prime through 3 iterations of function f(x) = 2x + 9.at n=18A023276
- Primes that remain prime through 3 iterations of function f(x) = 8x + 5.at n=12A023293
- Primes that remain prime through 4 iterations of function f(x) = 6x + 5.at n=16A023317
- Primes that remain prime through 4 iterations of function f(x) = 8x + 5.at n=0A023321
- a(n) = Sum_{k=1..n} k*[ (n/k)*[ n/k ] ].at n=46A024932
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 91.at n=12A031589
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 54 ones.at n=21A031822
- Super-4 Numbers (4 * n^4 contains substring '4444' in its decimal expansion).at n=4A032744
- Sequence of 2 Pythagorean triangles, each with a leg and hypotenuse prime. The leg of the second triangle is the hypotenuse of the first.at n=31A048270
- INVERT transform of factorial numbers.at n=7A051296
- Primes of the form 30*p + 1 where p is also prime.at n=24A051646
- Primes with distinct digits in descending order.at n=38A052014
- As p runs through the primes >= 5, sequence gives { numerator of Sum_{k=1..p-1} 1/k } / p^2.at n=4A061002
- Primes p for which the exponent of the highest power of 2 dividing p! is equal to prevprime(prevprime(p)).at n=35A064396
- a(n) = (n^3 + 24*n^2 + 65*n + 36)/6.at n=30A087863
- Primes p such that both the digit sum of p plus p and the digit product of p plus p are also primes.at n=31A092529
- Reduced numerators of the raw moments of the distribution of areas for triangles picked at random in a unit square.at n=14A093158
- a(n) = floor(11^n/7^n).at n=20A094993