15012
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 9
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 24
- Divisor Sum
- 39200
- Proper Divisor Sum (Aliquot Sum)
- 24188
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 4968
- Möbius Function
- 0
- Radical
- 834
- Omega Function (Ω)
- 6
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 164
- 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
- Row sums of A026584.at n=11A026596
- Totient of the Woodall numbers (A003261), n*2^n -1.at n=10A056821
- Variation of Stechkin's function, A055004.at n=15A062827
- Numbers k such that phi(sigma(k)+k) = sigma(k-phi(k)), where phi is A000010 and sigma is A000203.at n=32A063710
- Numbers whose sum of nonunitary divisors and sum of unitary divisors are both positive squares.at n=0A064730
- Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=1, r=4, I={3}.at n=16A079975
- Sizes of successive increasing gaps between 3-smooth numbers.at n=38A084788
- Difference between A007678(2n)/(2n) and (n-1)^2.at n=37A085611
- Records in A111229.at n=33A111270
- Row sums of unsigned triangle |A128495|=|S(2;n,m)| (sums of squares of Chebyshev's S-polynomials).at n=11A128496
- a(n) = ceiling(n*exp(csc(n))).at n=18A134900
- Positions of highly powerful numbers in the EKG sequence.at n=19A141422
- G.f. 1/[Sum_{n>=0} (2*n+1)*(-x)^(n*(n+1)/2)].at n=8A202143
- Triangle of coefficients of polynomials u(n,x) jointly generated with A209696; see the Formula section.at n=50A209695
- a(n) = Sum_{i=0..n} digsum_9(i)^3, where digsum_9(i) = A053830(i).at n=43A231686
- 100-gonal numbers: a(n) = 98*n*(n-1)/2 + n.at n=18A261276
- Numbers n such that sigma(n^3) is the sum of two positive cubes.at n=35A281364
- Indices i where a run of nonzero values starts in A305671.at n=26A305672
- Expansion of Sum_{k>=0} x^(k*(k+1)) / Product_{j=1..k} (1 - j*x^j).at n=30A306663
- a(n) is the smallest number that can be partitioned into n ways as the sum of two Moran numbers.at n=36A337862