1915
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 2304
- Proper Divisor Sum (Aliquot Sum)
- 389
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1528
- Möbius Function
- 1
- Radical
- 1915
- 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
- 174
- 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
- Number of bipartite partitions.at n=8A002765
- Number of simple tensors with n external gluons.at n=6A005415
- 3-Bell numbers: E.g.f.: exp(3*z + exp(z) - 1).at n=5A005494
- Coordination sequence T2 for Zeolite Code BOG.at n=31A008050
- Coordination sequence T3 for Zeolite Code PAU.at n=32A008221
- Coordination sequence for tridymite, lonsdaleite, and wurtzite.at n=27A008264
- arctanh(sin(arctanh(x))) = x + (3/3!)*x^3 + (49/5!)*x^5 + (1915/7!)*x^7 + (136225/9!)*x^9 + ...at n=3A012059
- arctanh(tan(arcsinh(x))) = x+3/3!*x^3+49/5!*x^5+1915/7!*x^7+143905/9!*x^9...at n=3A012166
- Expansion of 1/(1-x^4-x^5-x^6).at n=41A017828
- Expansion of 1/(1 - x^10 - x^11 - ...).at n=57A017904
- a(n) = round(Gamma(n+2/3)/Gamma(2/3)).at n=7A020043
- a(n) = floor(Gamma(n + 2/3)/Gamma(2/3)).at n=7A020088
- Numbers k such that the continued fraction for sqrt(k) has period 34.at n=12A020373
- Numbers k such that Fibonacci(k) == -5 (mod k).at n=51A023165
- Numbers with exactly 9 ones in binary expansion.at n=31A023691
- a(n) = Sum_{k=1..n} floor((n/k)*floor(n/k)).at n=34A024921
- Index of 10^n within the sequence of the numbers of the form 3^i*10^j.at n=42A025741
- Number of nonisomorphic semigroups of order n.at n=5A027851
- Numbers k such that the continued fraction for sqrt(k) has even period 2*m and the m-th term of the periodic part is 7.at n=29A031410
- Lucky numbers with size of gaps equal to 16 (upper terms).at n=5A031899