2801
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 11
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 2
- Divisor Sum
- 2802
- Proper Divisor Sum (Aliquot Sum)
- 1
- 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
- 2800
- Möbius Function
- -1
- Radical
- 2801
- Omega Function (Ω)
- 1
- Little Omega Function (ω)
- 1
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
- 35
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- yes
- Composite Number
- no
- Semiprime
- no
- Squarefree Number
- yes
- Prime Power
- yes
- Prime Factorization
- no
- Twin Prime
- yes
- Mersenne Prime
- no
- Sophie Germain Prime
- no
- Safe Prime
- no
- Powerful Number
- no
- Achilles Number
- no
- Prime Index
- 408
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Euclid-Mullin sequence: a(1) = 2, a(n+1) is smallest prime factor of 1 + Product_{k=1..n} a(k).at n=10A000945
- a(n) = solution to the postage stamp problem with 3 denominations and n stamps.at n=33A001208
- Quintan primes: p = (x^5 - y^5)/(x - y).at n=4A002649
- Primes of form (p^x - 1)/(p^y - 1), p prime.at n=13A003424
- Coordination sequence T3 for Zeolite Code EPI.at n=33A008092
- q-Fibonacci numbers for q=7, scaling a(n-2).at n=5A015464
- Expansion of 1/(1-x^4-x^5-x^6-x^7-x^8-x^9-x^10).at n=32A017832
- Cyclotomic polynomials at x=7.at n=5A019325
- Numbers k such that the continued fraction for sqrt(k) has period 47.at n=2A020386
- Cyclotomic polynomials at x = -7.at n=10A020506
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 7.at n=16A022171
- Triangle of Gaussian binomial coefficients [ n,k ] for q = 7.at n=19A022171
- Gaussian binomial coefficients [ n,4 ] for q = 7.at n=1A022233
- The sequence M(n) in A022905.at n=20A022908
- a(n) = (7^n - 1)/6.at n=5A023000
- Prime numbers that are the sum of the divisors of some n.at n=8A023195
- a(n) = T(2*n, n+2), T given by A027011.at n=4A027013
- a(n) = greatest number in row n of array T given by A027011.at n=12A027020
- a(n) = T(n, 2*n-7), T given by A027960.at n=8A027969
- a(n) = greatest number in row n of array T given by A027960.at n=12A027977