4155
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 15
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 6672
- Proper Divisor Sum (Aliquot Sum)
- 2517
- 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
- 2208
- Möbius Function
- -1
- Radical
- 4155
- 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
- 64
- 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
- Number of graphical basis partitions of 2n.at n=24A001130
- Total preorders.at n=5A006326
- Coordination sequence T4 for Zeolite Code VET.at n=39A009905
- Expansion of Product_{m>=1} 1/(1 - m*q^m)^5.at n=6A022729
- "DIJ" (bracelet, indistinct, labeled) transform of 1,3,5,7,...at n=6A032270
- Numbers k such that 159*2^k + 1 is prime.at n=25A032456
- Trajectory of 1 under map n->43n+1 if n odd, n->n/2 if n even.at n=33A033977
- Number of partitions of n into parts 4k and 4k+1 with at least one part of each type.at n=55A035621
- Number of partitions satisfying cn(0,5) = cn(2,5) + cn(3,5).at n=41A039859
- Denominators of continued fraction convergents to sqrt(341).at n=9A041645
- Consider all integer triples (i,j,k), j,k>0, with binomial(i+2, 3) = binomial(j+2, 3) + k^3, ordered by increasing i; sequence gives j values.at n=25A054222
- Numbers k such that k^12 == 1 (mod 13^3).at n=22A056086
- Second 11-gonal (or hendecagonal) numbers: a(n) = n*(9*n+7)/2.at n=30A062728
- Zero, together with positive numbers k such that prime(k) - k is a square.at n=23A064370
- Interprimes which are of the form s*prime, s=15.at n=23A075290
- Triangle T(n,k) read by rows; related to number of preorders.at n=26A079502
- a(n) = 4*n^2 + 10*n + 1.at n=31A082112
- Position of n-th n after the decimal point in Pi.at n=28A101196
- Numbers n such that prime(n) - n is a perfect power.at n=29A107607
- Numbers k such that k^4 + 4 is semiprime.at n=39A108814