2978
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 4470
- Proper Divisor Sum (Aliquot Sum)
- 1492
- 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
- 1488
- Möbius Function
- 1
- Radical
- 2978
- 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
- 48
- 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
- yes
- Odd
- no
Appears in sequences
- Conjecturally largest even integer which is an unordered sum of two primes in exactly n ways.at n=34A000954
- Number of unlabeled distributive lattices on n nodes.at n=17A006982
- Coordination sequence T5 for Zeolite Code HEU.at n=36A008120
- Coordination sequence T1 for Zeolite Code NON.at n=33A008212
- [ n(n-1)(n-2)(n-3)/11 ].at n=15A011921
- a(n+3) = 5*a(n+2)-4*a(n+1)+a(n).at n=7A012880
- Numbers whose least quadratic nonresidue (A020649) is 7.at n=41A025023
- Number of partitions of n into an even number of parts, the greatest being 6; also, a(n+11) = number of partitions of n+5 into an odd number of parts, each <=6.at n=50A026930
- Numbers k such that k^2 has only even digits.at n=46A030097
- Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 54.at n=6A031552
- Coordination sequence T2 for Zeolite Code CFI.at n=36A033600
- Numbers n such that BCR(n) = n, where BCR = binary-complement-and-reverse = take one's complement then reverse bit order.at n=45A035928
- Number of partitions satisfying (cn(2,5) = cn(3,5) = 0).at n=46A036820
- Numbers k such that the string 6,8 occurs in the base 9 representation of k but not of k-1.at n=40A044313
- Numbers n such that string 7,8 occurs in the base 10 representation of n but not of n-1.at n=32A044410
- Numbers n such that string 7,8 occurs in the base 10 representation of n but not of n+1.at n=32A044791
- Partial sums of A045954.at n=37A045964
- a(n) = a(n-1) + Sum_{k=0..n-3} a(k) for n >= 2, a(0)=1, a(1)=2.at n=15A049853
- Discriminants of real quadratic fields with class number 2 and related continued fraction period length of 8.at n=21A051973
- Expansion of (1-x)/(1 - x - x^2 - 3*x^3 + 3*x^4).at n=14A052915