15261
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 20352
- Proper Divisor Sum (Aliquot Sum)
- 5091
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 10172
- Möbius Function
- 1
- Radical
- 15261
- 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
- 177
- 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 k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 82.at n=32A031580
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 86 ones.at n=9A031854
- Gives an LCD representation of n.at n=40A071843
- Secondary diagonal of triangle A100235 divided by row number: a(n) = A100235(n+1,n)/(n+1) for n >= 0.at n=6A100237
- a(1) = 7, a(n) = least k such that concatenation of n copies of k with all previous concatenation gives a prime.at n=49A111475
- Start of record gap in odd semiprimes A046315.at n=9A114057
- Number of multi-trace BPS operators for the quiver gauge theory of the orbifold C^2/Z_2.at n=10A120844
- Coefficients of numerator polynomials S(n,x) associated with reciprocation.at n=44A147985
- Coefficients of numerator polynomials S(n,x) associated with reciprocation.at n=60A147985
- Coefficients of numerator polynomials P(n,x) associated with reciprocation.at n=44A147987
- Coefficients of numerator polynomials P(n,x) associated with reciprocation.at n=60A147987
- Coefficients of factor polynomials U(n,x) associated with reciprocation.at n=42A147989
- Array A147985 (Polynomial coefficients) with zeros deleted.at n=24A147990
- Array A147985 (Polynomial coefficients) with zeros deleted.at n=32A147990
- a(n) = 14*n^3 - 30*n^2 + 24*n - 7.at n=10A155883
- G.f. satisfies: A(x) = 1 + x*A(1 - 1/A(x))^2.at n=7A212411
- Where records occur in A114183.at n=39A222194
- a(n) = 9^(n-7) * (n+1)^(n-9) * (262144*n^7 + 2494464*n^6 + 10470208*n^5 + 25229505*n^4 + 37857568*n^3 + 35537670*n^2 + 19414368*n + 4782969).at n=4A251589
- Expansion of Product_{k>=1} ((1-x^(4*k))/(1-x^k))^k.at n=17A285262
- Number of maximal irredundant sets in the n-dipyramidal graph.at n=22A297711