15147
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
- 2
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 26136
- Proper Divisor Sum (Aliquot Sum)
- 10989
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 8640
- Möbius Function
- 0
- Radical
- 561
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 84
- 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
- no
- Odd
- yes
Appears in sequences
- Number of partitions of n into parts not of the form 25k, 25k+12 or 25k-12. Also number of partitions with at most 11 parts of size 1 and differences between parts at distance 11 are greater than 1.at n=36A036011
- Row sums of partition triangle A026820.at n=21A058397
- a(1) = 3; for n > 1, choose a(n) to be the smallest number such that a(n) > a(n-1) and (a(n)*a(n-1)+1) mod (a(n)+a(n-1)+1) = 0.at n=8A064457
- a(n) = n*(14*n-3).at n=33A185019
- Triangular array: the fission of (p(n,x)) by (q(n,x)), where p(n,x)=sum{F(k+1)*x^(n-k) : 0<=k<=n}, where F=A000045 (Fibonacci numbers) and q(n,x)=(x+1)^n.at n=49A193997
- Mirror of the triangle A193997.at n=50A193998
- Smallest number expressible in the form a^2 + 2b^2, with positive integers a and b, in exactly n ways.at n=9A200977
- Degrees of irreducible representations of orthogonal group O10-(2).at n=19A214475
- a(n) = [x^n] Product_{k>=1} ((1 + x^k)/(1 + x^(n*k)))^n.at n=8A304626
- Smallest number having exactly n divisors of the form 8*k + 1.at n=9A343104
- Smallest number having exactly n divisors of the form 8*k + 3.at n=10A343105
- Positions of records in A188169.at n=8A343134
- Positions of records in A188170.at n=8A343135
- Numbers m such that 20*m + 1, 80*m + 1, 100*m + 1, and 200*m + 1 are all primes.at n=21A372186
- a(n) is the smallest nonnegative integer k where there are exactly n nonnegative integer solutions to x^2 + 2*y^2 = k.at n=10A374285
- a(n) is the smallest positive integer k such that A002325(k) = n.at n=19A374294
- a(n) is the number of distinct solution sets to the quadratic equations u*x^2 + v*x + w = 0 with integer coefficients u, v, w, abs(u) + abs(v) + abs(w) <= n having a negative discriminant.at n=42A381710
- Expansion of e.g.f. 1/(1 - 2 * arctanh(x))^(1/2).at n=6A385468