1771
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- yes
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 2304
- Proper Divisor Sum (Aliquot Sum)
- 533
- 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
- 1320
- Möbius Function
- -1
- Radical
- 1771
- 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
- yes
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 55
- 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
- Tetrahedral (or triangular pyramidal) numbers: a(n) = C(n+2,3) = n*(n+1)*(n+2)/6.at n=21A000292
- a(n) = 1^2 + 3^2 + 5^2 + 7^2 + ... + (2*n-1)^2 = n*(4*n^2 - 1)/3.at n=11A000447
- Fermat coefficients.at n=9A000970
- Numbers of the form (p^2 - 1)/120 where p is 1 or prime.at n=42A002381
- Degrees of irreducible representations of Mathieu group M_24.at n=17A003859
- Degrees of irreducible representations of Conway group Co1.at n=3A003903
- Degrees of irreducible representations of Conway group Co3.at n=7A003910
- Degrees of irreducible representations of Conway group Co2.at n=4A003911
- Tetrahedral numbers written backwards.at n=21A004161
- Expansion of (1-x+x^2)/((1-x)^2*(1-x^2)*(1-x^4)).at n=41A005232
- Least k such that binomial(k,n) has n or more distinct prime factors.at n=37A005733
- Palindromic tetrahedral numbers.at n=3A006030
- Coordination sequence T2 for Zeolite Code MEP.at n=25A008158
- Molien series for cyclic group of order 5.at n=19A008646
- Expansion of 1/((1-x)^2*(1-x^2)*(1-x^4)).at n=40A008804
- Binomial coefficient C(23,n).at n=20A010939
- Binomial coefficient C(23,n).at n=3A010939
- a(n) = binomial(n,20).at n=3A010973
- a(n) = floor(C(n,4)/5).at n=23A011795
- Expansion of 1/((1-x)^2*Product_{k>=1} (1-x^k)).at n=14A014153