4121
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
- 4
- Divisor Sum
- 4452
- Proper Divisor Sum (Aliquot Sum)
- 331
- 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
- 3792
- Möbius Function
- 1
- Radical
- 4121
- 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
- 64
- 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
- Expansion of (2-2*x-x^2)/((1-2*x^2)*(1-x)^2).at n=24A016724
- Numbers k such that the continued fraction for sqrt(k) has period 25.at n=12A020364
- Fibonacci sequence beginning 1, 28.at n=12A022398
- Convolution of (F(2), F(3), F(4), ...) and odd numbers.at n=12A023652
- n written in fractional base 7/4.at n=29A024641
- Partial sums of A027035.at n=8A027036
- Numbers k such that 51*2^k+1 is prime.at n=28A032375
- Positive numbers for which the sum of digits equals the product of digits.at n=26A034710
- Positive numbers having the same set of digits in base 5 and base 10.at n=31A037433
- T(n,n-3), array T as in A038792.at n=29A038793
- Numerators of continued fraction convergents to sqrt(134).at n=7A041244
- Numerators of continued fraction convergents to sqrt(536).at n=5A042024
- Numbers whose base-16 representation has exactly 4 runs.at n=8A043677
- Numbers whose base-4 representation contains exactly three 0's and three 1's.at n=12A045031
- Numbers whose base-5 representation contains exactly three 1's and two 4's.at n=30A045261
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 23.at n=5A051988
- Number of rooted identity trees with n nodes and 7 leaves.at n=3A055332
- Product of the digits of n divides the sum of the digits of n.at n=36A055931
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 79 ).at n=16A063352
- Integers m such that (x1*x2*..xk)^(x1+x2+..xk) = (x1+x2+..xk)^(x1*x2*..xk) where x1x2..xk are the digits of m in base 10.at n=29A064158