945
domain: N
Properties
Digital Properties
- Digit Count
- 3
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 1920
- Proper Divisor Sum (Aliquot Sum)
- 975
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 432
- Möbius Function
- 0
- Radical
- 105
- Omega Function (Ω)
- 5
- 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
- 36
- Smith 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
Names
- German
- neunhundertfünfundvierzig· ordinal: neunhundertfünfundvierzigste
- English
- nine hundred forty-five· ordinal: nine hundred forty-fifth
- Spanish
- novecientos cuarenta y cinco· ordinal: 945º
- French
- neuf cent quarante-cinq· ordinal: neuf cent quarante-cinqième
- Italian
- novecentoquarantacinque· ordinal: 945º
- Latin
- nongenti quadraginta quinque· ordinal: 945.
- Portuguese
- novecentos e quarenta e cinco· ordinal: 945º
Appears in sequences
- a(n) = n*(n+3)/2.at n=42A000096
- Number of n-step spiral self-avoiding walks on hexagonal lattice, where at each step one may continue in same direction or make turn of 2*Pi/3 counterclockwise.at n=21A000511
- Generalized Stirling numbers of second kind.at n=3A000559
- Number of compositions of n into 3 ordered relatively prime parts.at n=53A000741
- Number of partitions of n into relatively prime parts. Also aperiodic partitions.at n=22A000837
- Number of twin prime pairs < square of n-th prime.at n=57A000885
- Double factorial of odd numbers: a(n) = (2*n-1)!! = 1*3*5*...*(2*n-1).at n=5A001147
- Triangle of coefficients of Bessel polynomials (exponents in decreasing order).at n=16A001497
- Triangle of coefficients of Bessel polynomials (exponents in decreasing order).at n=15A001497
- Triangle a(n,k) (n >= 0, 0 <= k <= n) of coefficients of Bessel polynomials y_n(x) (exponents in increasing order).at n=19A001498
- Triangle a(n,k) (n >= 0, 0 <= k <= n) of coefficients of Bessel polynomials y_n(x) (exponents in increasing order).at n=20A001498
- a(n) = 3^n + n^3.at n=6A001585
- a(n) = 6^n + n^6.at n=3A001594
- MacMahon's generalized sum of divisors function.at n=17A002127
- Denominators of zeta(2*n)/Pi^(2*n).at n=3A002432
- Numbers k such that (k^2 + k + 1)/13 is prime.at n=45A002642
- Numbers that are the sum of 2 positive cubes.at n=40A003325
- Divisors of 2^36 - 1.at n=56A003543
- Add 4, then reverse digits; start with 0.at n=27A003608
- Degrees of irreducible representations of alternating group A_12.at n=15A003867