15653
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 17088
- Proper Divisor Sum (Aliquot Sum)
- 1435
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 14220
- Möbius Function
- 1
- Radical
- 15653
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Schoenheim bound L_1(n,8,7).at n=13A036835
- Expansion of x*(-1+2*x-3*x^3+x^4)/((x^3+x^2+x-1) * (x-1)^2).at n=16A121986
- Expansion of psi(x^6) / psi(-x) in powers of x where psi() is a Ramanujan theta function.at n=45A132217
- a(n) = 8*n^2 + 20*n + 1.at n=43A161617
- Triangle read by rows: T(n,k) = binomial(n,k) + A008292(n+1,k+1) - 1.at n=31A176487
- Triangle read by rows: T(n,k) = binomial(n,k) + A008292(n+1,k+1) - 1.at n=32A176487
- Number of n X 2 arrays of the minimum value of corresponding elements and their horizontal, vertical, diagonal or antidiagonal neighbors in a random, but sorted with lexicographically nondecreasing rows and columns, 0..3 n X 2 array.at n=13A219454
- Number of 3 X n 0..2 arrays with horizontal differences mod 3 never 1, vertical differences mod 3 never -1, and rows and columns lexicographically nondecreasing.at n=35A229446
- Triangle read by rows: TR(m,n) is the Wiener index of the hexagonal trapezium T(m,n), defined in the He et al. reference (1 <= n <= m).at n=25A248095
- G.f. satisfies: A(x) = exp( Sum_{n>=1} [Sum_{k=0..3*n} T(n,k)^2 * x^k] / A(x)^n * x^n/n ) where T(n,k) equals the coefficient of x^k in (1+x+x^2+x^3)^n.at n=17A248876
- Expansion of f(-x, -x^5) * f(x, x^7) / f(-x, -x^2)^2 in powers of x where f(, ) is Ramanujan's general theta function.at n=22A262146
- Square roots of highly composite numbers, floored down: a(n) = A000196(A002182(n)).at n=60A263096
- Numbers k such that 3^k + k*2^k is prime.at n=14A270104
- Number of (undirected) paths in the n-helm graph.at n=10A292001
- Positive integers that have exactly nine representations of the form 1 + p1 * (1 + p2* ... * (1 + p_j)...), where [p1, ..., p_j] is a (possibly empty) list of distinct primes.at n=29A317399
- G.f. A(x) satisfies: A(x) = Sum_{n>=0} (n+1) * x^n / (1 - x^(n+1)*A(x)^n).at n=12A340359
- Numbers that are the sum of nine fourth powers in ten or more ways.at n=34A345594
- Numbers that are the sum of nine fourth powers in exactly ten ways.at n=28A345852