15958
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 24480
- Proper Divisor Sum (Aliquot Sum)
- 8522
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7800
- Möbius Function
- -1
- Radical
- 15958
- Omega Function (Ω)
- 3
- 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
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- Number of partitions satisfying cn(0,5) + cn(2,5) + cn(3,5) < cn(1,5) + cn(4,5).at n=38A039881
- Number of (n+2)X(1+2) 0..3 arrays with every 3X3 subblock row and column sum not 2 3 6 or 7 and every diagonal and antidiagonal sum 2 3 6 or 7.at n=14A251887
- Number of set partitions of [n] such that for each block all absolute differences between consecutive elements are <= three.at n=10A287275
- Sum of the fourth powers of the parts in the partitions of n into two parts.at n=9A294271
- The number of ways to tile (with squares and rectangles) a 2 X (n+2) strip with the upper left and upper right squares removed.at n=8A316726
- a(n) = Sum_{k=0..n} phi(k^2 + 1), where phi is the Euler totient function (A000010).at n=41A333170
- Let P(n) = primorial(n) = A002110(n); a(n) is the number of primes q < P(n) such that P(n) - q is also prime and q^2==1 (mod P(n)).at n=20A336093
- a(n) = A086330(prime(n)).at n=40A371035
- a(n) is the number of different hooklength lists of the plane partitions of n.at n=20A381332