2981
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
- 3264
- Proper Divisor Sum (Aliquot Sum)
- 283
- 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
- 2700
- Möbius Function
- 1
- Radical
- 2981
- 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
- 92
- 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
- Nearest integer to e^n.at n=8A000227
- Deceptive nonprimes: composite numbers k that divide the repunit R_{k-1}.at n=7A000864
- Powers of e rounded up.at n=8A001671
- A jumping problem.at n=15A002466
- Expansion of 1/((1-x)^3 (1-x^2)^2 (1-x^3) (1-x^4)).at n=15A002626
- Numbers that are the sum of 6 positive 6th powers.at n=23A003362
- Numbers k >= 2 such that if 1 < j < k then (fractional part of log k) < (fractional part of log j).at n=8A004790
- a(n) = ceiling(exp((n-1)/2)).at n=17A005181
- Pseudoprimes to base 10.at n=15A005939
- Coordination sequence T3 for Zeolite Code MEL.at n=35A008152
- Coordination sequence T4 for Zeolite Code -CLO.at n=48A009853
- (n,3,4) difference families over Z_n.at n=9A011994
- Number of 5-tuples of different integers from [ 1,n ] with no global factor.at n=14A015640
- Positive integers n such that 2^n == 2^11 (mod n).at n=44A015935
- Pseudoprimes to base 27.at n=25A020155
- Pseudoprimes to base 84.at n=11A020212
- Pseudoprimes to base 100.at n=25A020228
- Strong pseudoprimes to base 84.at n=3A020310
- Strong pseudoprimes to base 100.at n=10A020326
- Numbers k such that Fibonacci(k) == 89 (mod k).at n=38A023182