15930
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 32
- Divisor Sum
- 43200
- Proper Divisor Sum (Aliquot Sum)
- 27270
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4176
- Möbius Function
- 0
- Radical
- 1770
- Omega Function (Ω)
- 6
- Little Omega Function (ω)
- 4
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
- yes
- 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
- yes
- Odd
- no
Appears in sequences
- Numbers k such that 229*2^k+1 is prime.at n=14A032491
- Number of points in N^5 of norm <= n.at n=9A055404
- Number of points in N^n of norm <= 9.at n=5A055424
- 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, 0, 1), (0, 1, 1), (1, -1, 1), (1, 0, -1), (1, 1, 0)}.at n=7A150891
- Nine times hexagonal numbers: a(n) = 9*n*(2*n-1).at n=30A152994
- 5 times heptagonal numbers: a(n) = 5*n*(5*n-3)/2.at n=36A153785
- Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,4,0,2,1 for x=0,1,2,3,4.at n=5A197303
- Number of n X 6 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,4,0,2,1 for x=0,1,2,3,4.at n=3A197305
- 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 4,4,0,2,1 for x=0,1,2,3,4.at n=39A197307
- 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 4,4,0,2,1 for x=0,1,2,3,4.at n=41A197307
- a(2) = 1, then (p-1)*(p-4)/2, with p = prime(n), n > 2.at n=40A200050
- Number of squarefree words of length n in an n-ary alphabet, with new values 0..n-1 introduced in increasing order.at n=9A215070
- Numbers n such that either prime(n-1) == -1 (mod n) or prime(n+1) == -1 (mod n) but not both.at n=28A225318
- a(n) = n*(3*n^2 - 5*n + 3).at n=18A226450
- Numbers m such that the GCD of the x's that satisfy sigma(x) = m is 2.at n=39A241647
- Subsequence of lesser of 2 terms of A095301 that are 2 apart.at n=5A248083
- Indices of rows of triangle A262432 where the maximum term of the row is a new record.at n=26A262464
- G.f. A(x) satisfies: 1 = Sum_{n>=0} x^n * (1 + n*x)^n / A(x)^(n+1).at n=11A324614
- Number of compositions of n such that every distinct consecutive subsequence has a different sum.at n=31A325676
- Irregular table read by rows: Take a triangle with Pythagorean triple leg lengths with all diagonals drawn, as in A332978. Then T(n,k) = number of k-sided polygons in that figure for k >= 3 where the legs are divided into unit length parts.at n=35A333135