2679
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 3840
- Proper Divisor Sum (Aliquot Sum)
- 1161
- 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
- 1656
- Möbius Function
- -1
- Radical
- 2679
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 27
- Smith Number
- yes
- 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
- Expansion of tan(log(1+x)/cosh(x)).at n=7A009653
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly five 1's.at n=26A020441
- Quasi-Carmichael numbers to base -9: squarefree composites n such that prime p|n ==> p+9|n+9.at n=1A029569
- Least Smith number having digital sum A033662(n).at n=11A033663
- Number of twin primes < 2^n.at n=17A033843
- Number of partitions satisfying cn(1,5) < cn(2,5) + cn(3,5) and cn(4,5) < cn(2,5) + cn(3,5).at n=30A039888
- Denominators of continued fraction convergents to sqrt(425).at n=11A041809
- Numbers n such that string 0,6 occurs in the base 9 representation of n but not of n-1.at n=35A044257
- Numbers n such that string 7,9 occurs in the base 10 representation of n but not of n-1.at n=28A044411
- Numbers n such that string 0,6 occurs in the base 9 representation of n but not of n+1.at n=35A044638
- Numbers n such that string 6,7 occurs in the base 10 representation of n but not of n+1.at n=29A044780
- Numbers n such that string 7,9 occurs in the base 10 representation of n but not of n+1.at n=28A044792
- a(1) = 4; a(n) is smallest number >= a(n-1) such that the juxtaposition a(1)a(2)...a(n) is a prime.at n=27A046254
- Coordination sequence T2 for Zeolite Code DON.at n=35A047954
- Coordination sequence T5 for Zeolite Code DON.at n=35A047957
- Truncated triangular pyramid numbers: a(n) = Sum_{k=9..n} (k*(k+1)/2 - 45).at n=18A051943
- Concatenation of n in base 2 up to base 10 is prime, all numbers are interpreted as decimals.at n=25A054256
- a(n) = 4*n^2 - 9*n + 6.at n=26A054556
- Number of trees with n nodes and 6 leaves.at n=9A055293
- Position of first occurrence of 2^n in A057923.at n=17A057925