17881
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 17882
- 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
- 17880
- Möbius Function
- -1
- Radical
- 17881
- 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
- 48
- 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
- 2049
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Prime(n)*...*a(n) is the least product of consecutive primes which is non-deficient.at n=30A007686
- Prime(n)*...*a(n) is the least product of consecutive primes which is abundant.at n=30A007708
- Primes that divide at least one term of Sylvester's sequence s = A000058: s(n+1) = s(n)^2 - s(n) + 1, s(0) = 2.at n=29A007996
- Least inverse of A001390, or 0 if no inverse exists.at n=40A020638
- Primes that remain prime through 3 iterations of function f(x) = 2x + 9.at n=36A023276
- Primes that remain prime through 3 iterations of function f(x) = 9x + 4.at n=35A023297
- Primes that remain prime through 4 iterations of function f(x) = 3x + 10.at n=15A023310
- Number of irreducible representations of symmetric group S_n for which every matrix has determinant 1.at n=35A045923
- a(n) = prime(2^n + 1).at n=11A051439
- Primes p for which the period of reciprocal = (p-1)/8.at n=28A056213
- a(n) = n^2 concatenated with reverse(n^2) divided by 11.at n=14A084009
- Primes p giving prime quadruples (30p+11, 30p+13, 30p+17, 30p+19).at n=11A087771
- Primes p such that the sum of the digits of p is not prime, but the sum of the squares of the digits of p is prime.at n=36A091362
- Smallest prime a such that (a*b)^2 + a*b -1 is prime with b prime = 2^(2*n) - 2^n - 1, see A098845 for n.at n=25A107639
- Numbers k such that k, k+1, k+2 and k+3 are 1,2,3,4-almost primes.at n=18A113000
- Primes in the sequence A003294 of certain fourth powers bases.at n=10A134820
- Primes of the form 76x^2+20xy+145y^2.at n=34A140629
- Primes congruent to 20 mod 53.at n=37A142550
- Primes congruent to 4 mod 59.at n=35A142731
- Primes congruent to 8 mod 61.at n=37A142806