15689
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 29
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 16260
- Proper Divisor Sum (Aliquot Sum)
- 571
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 15120
- Möbius Function
- 1
- Radical
- 15689
- 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
- yes
- 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
- Numbers that are the sum of 2 nonzero 6th powers.at n=11A003358
- Numbers that are the sum of at most 2 nonzero 6th powers.at n=17A004853
- Numbers that are the sum of at most 3 nonzero 6th powers.at n=38A004854
- Sum of 6th powers of digits of n.at n=25A055015
- Numbers k such that sigma(phi(sigma(k))) = phi(k).at n=12A066465
- a(n) = 2^n + 5^n.at n=6A074600
- Expansion of (1-x)/(1+x+2*x^2+x^3).at n=40A078051
- Numbers that can be represented as j^6 + k^6, with 0 < j < k, in exactly one way.at n=7A088677
- Primitive sliding numbers (excludes multiples of 10): totals, including repetitions, of sums r + s, r >= s, such that 1/r + 1/s = (r + s)/10^k for some k >= 0.at n=31A103184
- Integers 1 through n written in primorial base, summed as if decimal.at n=36A122613
- Numbers that are sums of sixth powers of two distinct primes.at n=1A130555
- Table T(k,n) read along antidiagonals: sum of the k-th powers of the distinct prime factors of A024619(n).at n=22A138296
- a(1)=1, a(n)=a(n-1)+n^1 if n odd, a(n)=a(n-1)+ n^4 if n is even.at n=9A140146
- Triangle T(n,m,p,q) = (p^(n-k)*q^k + p^k*q^(n-k))*(StirlingS2(n, k) + StirlingS2(n, n-k)) with p=2 and q=5, read by rows.at n=21A154922
- Triangle T(n,m,p,q) = (p^(n-k)*q^k + p^k*q^(n-k))*(StirlingS2(n, k) + StirlingS2(n, n-k)) with p=2 and q=5, read by rows.at n=27A154922
- Hypotenuses c of primitive Pythagorean Triples (a,b,c) such that 2*a+1, 2*b+1 and 2*c+1 are primes.at n=35A165238
- a(0)=0, a(1)=1, a(2)=2 and a(n) = a(n-1) - 2a(n-2) + a(n-3).at n=41A166117
- Sum of a positive square and a positive cube in at least three ways.at n=27A171385
- Numerators of the rational sequence with e.g.f. (x/2)*(exp(-x) + 1)/(exp(x) - 1).at n=12A176328
- First string of 43 consecutive composite numbers.at n=5A177949