9239
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 9240
- 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
- 9238
- Möbius Function
- -1
- Radical
- 9239
- 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
- 153
- 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
- 1145
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numerators of convergents to cube root of 5.at n=10A002358
- Number of unrooted achiral trees with n nodes.at n=33A003244
- Number of sensed planar maps with n edges and without loops or isthmuses.at n=10A006398
- a(n) = a(n-1) + a(n-2) + F(n) - 1, a(0) = a(1) = 0, where F() = Fibonacci numbers A000045.at n=16A006478
- Coordination sequence for alpha-Mn, Position Mn1.at n=25A009950
- Numbers such that ten iterations of Reverse and Add are needed to reach a palindrome.at n=4A015991
- Numbers k such that the continued fraction for sqrt(k) has period 88.at n=18A020427
- Let q_k=p(p+2) be product of k-th pair of twin primes; sequence gives values of p such that (q_k)^2 > q_{k-i}q_{k+i} for all 1 <= i <= k-1.at n=46A021005
- Primes that remain prime through 3 iterations of function f(x) = 7x + 6.at n=17A023290
- Numbers whose least quadratic nonresidue (A020649) is 19.at n=1A025027
- 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 95.at n=19A031593
- Primes with first digit 9.at n=42A045715
- Numbers n such that 183*2^n-1 is prime.at n=18A050843
- Primes p such that x^31 = 2 has no solution mod p.at n=34A059225
- Smaller of twin primes whose middle term is a multiple of A002110(4)=210.at n=11A060230
- Smaller of twin primes whose middle term is a multiple of A002110(5)=2310.at n=1A060231
- Primes with 19 as smallest positive primitive root.at n=8A061331
- Primes starting and ending with 9.at n=8A062335
- Numbers which need ten 'Reverse and Add' steps to reach a palindrome.at n=4A065215
- Primes p such that the number of distinct prime divisors of all composite numbers between p and the next prime is 5.at n=16A075585