15588
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
- 18
- Divisor Sum
- 39494
- Proper Divisor Sum (Aliquot Sum)
- 23906
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 5184
- Möbius Function
- 0
- Radical
- 2598
- Omega Function (Ω)
- 5
- 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
- 146
- 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
- yes
- Odd
- no
Appears in sequences
- Totient(n) and cototient(n) are squares.at n=43A054754
- Numbers k such that phi(k) and cototient(k) are squares but k is not in A054755.at n=11A054756
- (Sum of digits of n)^6 - (sum of digits of n^6).at n=14A069980
- (Sum of digits of n)^6 - (sum of digits of n^6).at n=32A069980
- Number of solutions to n^2 < x^2 + y^2 + z^2 < (n+1)^2; number of lattice points between spheres of radii n and n+1.at n=35A078184
- Chebyshev polynomials S(n,11) + S(n-1,11) with Diophantine property.at n=4A097783
- Structured pentagonal icositetrahedral numbers (vertex structure 13).at n=11A100167
- a(n) = (p-1)! mod p^2 where p = n-th prime.at n=31A112660
- Row sums of correlation triangle for floor((n+3)/3).at n=46A115266
- Triangle read by rows, derived from an array of sequences generated from (1 + x)/ (1 - r*x - r*x^2).at n=60A180165
- a(0) = 1, a(1) = 7; a(n)= 6*a(n-1) + 6*a(n-2) for n>1.at n=5A180167
- Numbers that begin a run of an odd number of consecutive integers whose cubes sum to a square.at n=11A253679
- Numbers m such that A166133(m+1) = A166133(m)^2 - 1.at n=24A256703
- Sum of the squares of the larger parts of the partitions of 2n into two squarefree parts.at n=21A280322
- Number of unique X-rays of n X n binary matrices with exactly n ones.at n=30A290133
- O.g.f. A(x) satisfies: Sum_{n>=1} (x + (-1)^n*A(x))^n / n = 0.at n=8A316363
- G.f.: Sum_{k>=0} x^(k^3) / Product_{j=1..k^3} (1 - x^j).at n=51A334626
- Numbers that are the sum of nine fourth powers in ten or more ways.at n=32A345594
- Numbers that are the sum of nine fourth powers in exactly ten ways.at n=26A345852
- a(n) = Sum_{k=1..n} phi(n*k).at n=36A372608