2465
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 17
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3240
- Proper Divisor Sum (Aliquot Sum)
- 775
- 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
- 1792
- Möbius Function
- -1
- Radical
- 2465
- 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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 71
- 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
- yes
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Octagonal numbers: n*(3*n-2). Also called star numbers.at n=29A000567
- Fermat pseudoprimes to base 2, also called Sarrus numbers or Poulet numbers.at n=8A001567
- Carmichael numbers: composite numbers k such that a^(k-1) == 1 (mod k) for every a coprime to k.at n=3A002997
- Number of nonequivalent dissections of an n-gon into 3 polygons by nonintersecting diagonals up to rotation.at n=28A003451
- Number of walks on cubic lattice.at n=16A005570
- Bruckman-Lucas pseudoprimes: k | (L_k - 1), where k is composite and L_k = Lucas numbers A000032.at n=1A005845
- Rhombic dodecahedral numbers: a(n) = n^4 - (n - 1)^4.at n=8A005917
- Pseudoprimes to base 3.at n=10A005935
- Pseudoprimes to base 6.at n=10A005937
- Pseudoprimes to base 7.at n=10A005938
- a(n) = n*(n^2 + 1)/2.at n=17A006003
- Odd numbers not of form p + 2^k (de Polignac numbers).at n=56A006285
- Denominator of (2n+1)(2n+2) B_{2n}, where B_n are the Bernoulli numbers. Also denominators of the asymptotic expansion of the polygamma function psi'''(z).at n=57A006956
- Euler pseudoprimes: composite numbers n such that 2^((n-1)/2) == +-1 (mod n).at n=6A006970
- Composite numbers k such that k == +-1 (mod 8) and 2^((k-1)/2) == 1 (mod k).at n=5A006971
- Expansion of e.g.f. tanh(exp(x)*x).at n=7A009768
- Orders of cyclotomic polynomials containing a coefficient the absolute value of which is >= 3.at n=28A013591
- Odd octagonal numbers: (2n+1)*(6n+1).at n=14A014641
- a(n) = 9^n - 8^n.at n=4A016185
- Fermat pseudoprimes to base 4.at n=20A020136