4187
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4320
- Proper Divisor Sum (Aliquot Sum)
- 133
- 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
- 4056
- Möbius Function
- 1
- Radical
- 4187
- 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
- yes
- Hexagonal Number
- no
- Lucas Number
- no
- Tetrahedral Number
- no
- Pell Number
- no
- Tribonacci Number
- no
- Pronic Number
- no
Recreational
- Happy Number
- yes
- 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
- Deceptive nonprimes: composite numbers k that divide the repunit R_{k-1}.at n=10A000864
- G.f.: x*(1-x^2)*(x^4+x^3-x^2+x+1) / (x^8-4*x^6-x^4-4*x^2+1).at n=13A005822
- Pseudoprimes to base 10.at n=19A005939
- Numbers k such that sigma(k+2) = sigma(k).at n=13A007373
- Prime(n)*...*prime(a(n)) is the least product of consecutive primes that is non-deficient.at n=42A007684
- Prime(n)*...*prime(a(n)) is the least product of consecutive primes which is abundant.at n=42A007707
- Odd pentagonal numbers.at n=26A014632
- Pseudoprimes to base 15.at n=13A020143
- Pseudoprimes to base 17.at n=19A020145
- Pseudoprimes to base 38.at n=31A020166
- Pseudoprimes to base 46.at n=40A020174
- Pseudoprimes to base 52.at n=19A020180
- Pseudoprimes to base 57.at n=34A020185
- Pseudoprimes to base 62.at n=33A020190
- Pseudoprimes to base 69.at n=23A020197
- Pseudoprimes to base 78.at n=18A020206
- Pseudoprimes to base 89.at n=44A020217
- Pseudoprimes to base 91.at n=36A020219
- Pseudoprimes to base 93.at n=31A020221
- Pseudoprimes to base 96.at n=21A020224