2170
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 10
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 4608
- Proper Divisor Sum (Aliquot Sum)
- 2438
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 720
- Möbius Function
- 1
- Radical
- 2170
- Omega Function (Ω)
- 4
- Little Omega Function (ω)
- 4
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
- yes
- Narcissistic Number
- no
- Collatz Steps
- 45
- Smith Number
- no
- 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
- yes
- Odd
- no
Appears in sequences
- Partial sums of A006206.at n=19A001461
- Numbers k such that phi(k) = phi(k+2).at n=35A001494
- Numbers k such that 5*2^k - 1 is prime.at n=24A001770
- Numbers k such that the k-th tetrahedral number is the sum of 2 tetrahedral numbers.at n=46A002311
- Primitive pseudoperfect numbers.at n=35A006036
- Number of partitions of n with at least 1 odd and 1 even part.at n=26A006477
- Coordination sequence T1 for Zeolite Code TON.at n=29A008241
- If a, b in sequence, so is ab+6.at n=25A009307
- Coordination sequence T1 for Keatite.at n=26A009844
- cosh(arctan(x)*exp(x))=1+1/2!*x^2+6/3!*x^3+17/4!*x^4+20/5!*x^5...at n=7A012417
- cosh(arcsinh(x)*exp(x))=1+1/2!*x^2+6/3!*x^3+21/4!*x^4+60/5!*x^5...at n=7A012593
- a(n) = (n+2)*(n+1)*(n^2 + 7*n - 12)/24.at n=12A014309
- a(n) = [ a(n-1)/a(1) ] + [ a(n-2)/a(2) ] + ... + [ a(1)/a(n-1) ], for n >= 3.at n=25A022870
- Numbers k such that Fibonacci(k) == 55 (mod k).at n=33A023181
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = A023532, t = A001950 (upper Wythoff sequence).at n=52A024374
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n+1-k), where k = [ (n+1)/2 ], s = (composite numbers), t = (odd natural numbers).at n=16A024590
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = A023532, t = A001950 (upper Wythoff sequence).at n=51A025074
- a(n) = s(1)t(n) + s(2)t(n-1) + ... + s(k)t(n-k+1), where k = [ n/2 ], s = (Lucas numbers), t = A000201 (lower Wythoff sequence).at n=15A025094
- Number of distinct prime signatures of the positive integers up to 2^n.at n=34A025488
- dot product (n,n-1,...2,1).(3,4,...,n,1,2).at n=18A026054