4040
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 8
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 9180
- Proper Divisor Sum (Aliquot Sum)
- 5140
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 1600
- Möbius Function
- 0
- Radical
- 1010
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 64
- Smith Number
- no
- Vampire 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
- yes
- Odd
- no
Appears in sequences
- Number of compositions of n into 4 ordered relatively prime parts.at n=28A000742
- Number of n-step self-avoiding walks on hexagonal lattice from (0,0) to (0,1).at n=8A003289
- 'Eban' numbers (the letter 'e' is banned!).at n=47A006933
- 9-gonal (or enneagonal) pyramidal numbers: a(n) = n*(n+1)*(7*n-4)/6.at n=15A007584
- Coordination sequence T1 for Zeolite Code APC.at n=44A008032
- Expansion of tanh(x).exp(tan(x)).at n=8A009830
- Spontaneous magnetization coefficients for square lattice spin 1 Ising model.at n=19A010102
- Expansion of 1/((1-9x)(1-11x)).at n=3A016190
- Doublets: base-10 representation is the juxtaposition of two identical strings.at n=39A020338
- a(n) = 3rd elementary symmetric function of the first n+2 positive integers congruent to 2 mod 3.at n=2A024392
- n written in fractional base 8/4.at n=40A024646
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 31.at n=19A031529
- Number of points of l_1 norm n in the "diamond" lattice D^+_4.at n=10A035878
- Coordination sequence T2 for Zeolite Code DON.at n=43A047954
- Numbers whose consecutive digits differ by 4.at n=39A048406
- Positions in decimal expansion of Pi where next prime begins.at n=36A053013
- Number of basis partitions of n+25 with Durfee square size 5.at n=24A053800
- Numbers k such that k^18 == 1 (mod 19^3).at n=11A056089
- Number of 2 X n checkerboards (with at least one red square) in which the set of red squares is edge connected.at n=8A059020
- Number of distinct Cunningham chains of first kind whose initial prime (cf. A059453) <= 2^n.at n=18A059690