15881
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 15882
- 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
- 15880
- Möbius Function
- -1
- Radical
- 15881
- 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
- 128
- 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
- 1850
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Fibonacci sequence beginning 5, 13.at n=16A022138
- Primes that remain prime through 3 iterations of function f(x) = 4x + 9.at n=37A023282
- a(n+1) = a(n) converted to base 5 from base 3 (written in base 10).at n=7A023368
- Numerators of continued fraction convergents to sqrt(846).at n=9A042632
- Numbers whose base-5 representation contains exactly three 0's and three 1's.at n=37A045172
- Smallest prime in n-th shell of prime spiral.at n=22A053998
- Primes of the form k^2 + 5.at n=9A056905
- Diagonal of triangle in A082737.at n=33A082738
- Primes of the form a^4 + b^3 with b>0.at n=32A100271
- Primes q of the form a^3+b^2, such that p =A130467(n)= a^2+b^3 is prime and smaller than q; p < q ; b < a.at n=32A130468
- Primes of the form a^a + b^b + c^c + d^d + e^e + f^f.at n=25A136294
- Primes congruent to 42 mod 47.at n=35A142393
- Primes congruent to 34 mod 53.at n=34A142564
- Primes congruent to 10 mod 59.at n=33A142737
- Primes congruent to 21 mod 61.at n=30A142819
- a(n) = Sum_{k<=n} A000203(k)*(n-k+1), where A000203(m) is the sum of divisors of m.at n=37A175254
- Primes in A002049.at n=16A185846
- Number of nX4 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 0 1 and 1 1 1 vertically.at n=8A207510
- Primes which are the sum of two numbers of the form k*(k+1)^2/2.at n=36A210646
- a(n) is the number of representative two-color bracelets (necklaces with turnover allowed) with n beads for n >= 2.at n=18A213942