2979
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 6
- Divisor Sum
- 4316
- Proper Divisor Sum (Aliquot Sum)
- 1337
- 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
- 1980
- Möbius Function
- 0
- Radical
- 993
- Omega Function (Ω)
- 3
- 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
- no
- Squarefree Number
- no
- 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
- Divisors of 2^30 - 1.at n=29A003538
- Number of 1-supertough but non-1-Hamiltonian simplicial polyhedra with n nodes.at n=13A007036
- Coordination sequence T1 for Zeolite Code EUO.at n=34A008095
- Coordination sequence T1 for Zeolite Code VFI.at n=42A008245
- Numbers k such that the continued fraction for sqrt(k) has period 38.at n=29A020377
- Ordered sequence of distinct terms of the form floor(exp(i) * floor(exp(j))), i,j >= 0.at n=34A022765
- a(n) = d(n)/2, where d = A026040.at n=23A026041
- Numbers k such that k^2 has digits in nonincreasing order.at n=28A028821
- 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 53.at n=16A031551
- Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 22 ones.at n=37A031790
- Number of partitions of n into parts 4k or 4k+1.at n=51A035362
- Numerators of continued fraction convergents to sqrt(695).at n=4A042336
- Numbers n such that string 7,9 occurs in the base 10 representation of n but not of n-1.at n=32A044411
- Numbers n such that string 7,9 occurs in the base 10 representation of n but not of n+1.at n=32A044792
- Numbers n such that string 9,7 occurs in the base 10 representation of n but not of n+1.at n=31A044810
- Numbers whose base-5 representation contains exactly one 0 and three 4's.at n=31A045209
- Numbers whose base-5 representation contains exactly one 3 and three 4's.at n=36A045299
- a(n) = Sum_{m=1..n, k=1..m} T(m,k), array T as in A049834.at n=26A049836
- Consider a room of size r X s where rs = 2n and 1 <= r <= s; count ways to arrange n Tatami mats in room; a(n) = total number of ways for all choices of r and s. Two arrangements are considered the same if one is a rotation or reflection of the other.at n=22A052270
- Number of bracelets of length n using exactly three different colored beads.at n=9A056343