15885
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 27612
- Proper Divisor Sum (Aliquot Sum)
- 11727
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8448
- Möbius Function
- 0
- Radical
- 5295
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 3
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
- 53
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- Squarefree Number
- no
- Prime Power
- no
- Prime Factorization
- no
- Twin Prime
- no
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 28.at n=8A031706
- Numbers k such that the decimal part of k^(1/7) starts with a 'nine digits' anagram.at n=7A034282
- Numbers k such that k^2 contains only digits {2,3,5}.at n=6A053918
- Indices of primes in the sequence defined by A(0) = 29, A(n) = 10*A(n-1) - 31 for n > 0.at n=6A101963
- Numbers n such that p(8n) is prime, where p(n) is the number of partitions of n.at n=25A114168
- Numbers k such that 2k+1, 4k+1, 6k+1 and 8k+1 are primes.at n=12A124409
- Numbers k such that 2*k+1, 4*k+1, 8*k+1 and 16*k+1 are primes.at n=17A124412
- Numbers k such that k and k^2 use only the digits 1, 2, 3, 5 and 8.at n=24A136976
- a(n) = 81*n^2 + 9.at n=13A157888
- a(n) = 44*n^2 + 1.at n=19A158630
- Number of n X 3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,3,0,1 for x=0,1,2,3,4.at n=8A196804
- T(n,k)=Number of nXk 0..4 arrays with each element x equal to the number of its horizontal and vertical neighbors equal to 4,2,3,0,1 for x=0,1,2,3,4.at n=57A196809
- Where records occur in A214323.at n=11A214325
- a(n) = Sum_{i=0..n} digsum(i)^3, where digsum(i) = A007953(i).at n=42A231688
- Numbers m such that each of p=6*m+1, q=6*p+1, r=6*q+1 and s=6*r+1 is prime.at n=22A263311
- Numbers n such that the decimal digits of n^2 are all prime.at n=12A275971
- Number of theorems in the MIU formal system which can be proved in n steps or fewer starting with the axiom 'mi'.at n=8A331536
- a(n) = Sum_{k=1..n} (A000330(n) mod k^2).at n=41A344711
- a(n) is the least base in which the Fibonacci number A000045(n) is a palindrome.at n=60A372754