15574
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 22
- Digital Root
- 4
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 25200
- Proper Divisor Sum (Aliquot Sum)
- 9626
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 7176
- Möbius Function
- -1
- Radical
- 15574
- 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
- 71
- 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
- Character of extremal vertex operator algebra of rank 13.at n=4A028534
- Expansion of (1+x^2*C^2)*C^3, where C = (1-(1-4*x)^(1/2))/(2*x) is g.f. for Catalan numbers, A000108.at n=8A071722
- Number of compositions of n into Fibonacci numbers (1 counted as single Fibonacci number).at n=16A076739
- Numbers n such that P(13*n) is prime, where P(n) is the unrestricted partition number.at n=14A113518
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 0), (-1, 0, 0), (-1, 1, -1), (0, 1, 1), (1, -1, 0)}.at n=10A148344
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, -1, 1), (-1, 0, 0), (-1, 1, -1), (0, 1, 1), (1, -1, 0)}.at n=10A148345
- Number of binary strings of length n with no substrings equal to 0000 0101 or 1110.at n=16A164436
- Number of n X 6 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.at n=6A201373
- Number of nX7 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.at n=5A201374
- T(n,k)=Number of nXk 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.at n=71A201375
- T(n,k)=Number of nXk 0..1 arrays with rows and columns lexicographically nondecreasing read forwards, and nonincreasing read backwards.at n=72A201375
- Number of ordered triples (w,x,y) with all terms in {1,...,n} and 2w^3>x^3+y^3.at n=32A211811
- a(n) = Fibonacci(p) mod p^2, where p = prime(n).at n=40A236395
- Expansion of f(-x^3, -x^5) * f(x^3, x^13) / (f(-x, -x^2) * f(-x^8, -x^16)) in powers of x where f(, ) is Ramanujan's general theta function.at n=42A258939
- a(n) = (n + 2)*(n^2 + n - 1).at n=24A318765
- Number of parts in all twice partitions of n where the first partition is strict.at n=13A327607
- a(n) is the least integer k such that A366110(k) = n, or 0 if there is no such k.at n=77A365619
- a(n) = Sum_{k=1..n-1} tau(k) * sigma_2(n-k).at n=24A374973
- G.f.: Sum_{k>=0} x^(k^2) / Product_{j=1..k} (1 - x^(2*j-1))^2.at n=45A376581