2212
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 7
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 4480
- Proper Divisor Sum (Aliquot Sum)
- 2268
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- yes
Derived Values
- Euler's Totient
- 936
- Möbius Function
- 0
- Radical
- 1106
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 138
- 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
- yes
- Odd
- no
Appears in sequences
- a(0) = a(1) = 1; for n > 0, a(n+1) = a(n)*(a(0) + ... + a(n-1)) + a(n)*(a(n) + 1)/2.at n=5A002658
- Cubes written in base 6.at n=7A004636
- Powers of 2 written in base 6.at n=9A004645
- Numbers that contain only 1's and 2's. Nonempty binary strings of length n in lexicographic order.at n=27A007931
- Coordination sequence T1 for Zeolite Code LOV.at n=31A008134
- Coordination sequence T5 for Zeolite Code MFS.at n=29A008177
- Coordination sequence T2 for Zeolite Code DFO.at n=36A009876
- Shifts 5 places right under binomial transform.at n=12A010744
- Shifts 5 places left under inverse binomial transform.at n=17A010745
- a(1) = 1, a(n) = Sum_{k=1..n-1} ((12^k - 1)/11)*a(k).at n=3A015515
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A000201 (lower Wythoff sequence), t = A001950 (upper Wythoff sequence).at n=17A024686
- s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A000201 (lower Wythoff sequence), t = A001950 (upper Wythoff sequence).at n=16A025119
- a(n) = [ 2nd elementary symmetric function of {log(k)} ], k = 2,3,...,n.at n=25A025202
- Decimal expansion of a(n) is given by the first n terms of the periodic sequence with initial period 2,2,1.at n=3A037567
- a(n) = (9*n^2 + 3*n + 2)/2.at n=22A038764
- k th digit of a(n) = number of different digits within 2 places of k (not including k).at n=8A039987
- k th digit of a(n) is the number of different digits within 3 of k (not including k).at n=8A039989
- k th digit of a(n) is the number of different digits within 4 of k (not including k).at n=8A039990
- Numbers having three 4's in base 8.at n=6A043439
- Numbers having three 2's in base 10.at n=5A043499