1865
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
- 4
- Divisor Sum
- 2244
- Proper Divisor Sum (Aliquot Sum)
- 379
- 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
- 1488
- Möbius Function
- 1
- Radical
- 1865
- 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
- 68
- 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
- Year of birth of n-th President of U.S.A.at n=28A008745
- Triangle of coefficients from fractional iteration of e^x - 1.at n=12A008826
- Coordination sequence T5 for Zeolite Code DFO.at n=33A009879
- a(0) = 1, a(n) = 23*n^2 + 2 for n>0.at n=9A010013
- a(1)=1, a(n) = 6*a(n-1) + n.at n=4A014829
- Coordination sequence T5 for Zeolite Code TER.at n=29A016437
- Numbers k such that the continued fraction for sqrt(k) has period 11.at n=17A020350
- Positive numbers k such that k and 3*k are anagrams in base 9 (written in base 9).at n=19A023080
- Numbers k such that Fibonacci(k) == -5 (mod k).at n=50A023165
- Base 6 expansion uses each positive digit just once.at n=0A023744
- Metadromes: digits in base 6 are in strict ascending order.at n=31A023775
- Largest metadrome (number with digits in strict ascending order) in base n.at n=5A023811
- Numbers with exactly five distinct base-6 digits.at n=33A031983
- Coordination sequence T4 for Zeolite Code STF.at n=29A038439
- Numbers k such that gcd(phi(k), k-1) = number of divisors of (k-1).at n=37A039768
- Numbers k such that 5 and 6 occur juxtaposed in the base-10 representation of k but not of k-1.at n=37A043251
- Numbers k such that 5 and 6 occur juxtaposed in the base-10 representation of k but not of k+1.at n=37A044031
- Numbers k such that string 0,3 occurs in the base 7 representation of k but not of k-1.at n=42A044141
- Numbers n such that string 1,1 occurs in the base 8 representation of n but not of n-1.at n=29A044196
- Numbers n such that string 0,2 occurs in the base 9 representation of n but not of n-1.at n=24A044253