2945
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3840
- Proper Divisor Sum (Aliquot Sum)
- 895
- 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
- 2160
- Möbius Function
- -1
- Radical
- 2945
- Omega Function (Ω)
- 3
- 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
- 79
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- no
- 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
- a(n) = ceiling(1000*log(n)).at n=18A004242
- Coordination sequence T2 for Zeolite Code LTL.at n=40A008139
- Number of partitions of n into parts >= 4.at n=50A008484
- Coordination sequence T1 for Zeolite Code ZON.at n=38A009919
- Coordination sequence T2 for Zeolite Code ZON.at n=38A009920
- Shifts 2 places right under binomial transform.at n=9A010738
- Shifts 2 places left under inverse binomial transform.at n=11A010739
- Numbers k such that the geometric mean of phi(k) and sigma(k) is an integer.at n=34A011257
- sech(sec(x)*tanh(x))=1-1/2!*x^2+1/4!*x^4-97/6!*x^6+2945/8!*x^8...at n=4A012839
- Geometric mean of phi(n) and sigma(n) is an integer, n odd.at n=14A015705
- Pseudoprimes to base 94.at n=31A020222
- Base 6 expansion uses each positive digit just once.at n=24A023744
- Number of partitions of n in which the least part is 4.at n=53A026797
- Coordination sequence T4 for Zeolite Code CGS.at n=40A027368
- a(n) = Sum_{d|n} sigma(n/d)*d^3.at n=11A027847
- a(n) = (prime(n)-1)*(prime(n)-5)/12.at n=40A030006
- Multiplicity of highest weight (or singular) vectors associated with character chi_19 of Monster module.at n=34A034407
- Number of partitions of n such that cn(0,5) = cn(1,5) <= cn(3,5) <= cn(2,5) = cn(4,5).at n=59A036864
- Positive numbers having the same set of digits in base 5 and base 9.at n=34A037432
- Indices of primes at which the prime race 4k-1 vs. 4k+1 is tied.at n=6A038691