2152
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
- 2
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 4050
- Proper Divisor Sum (Aliquot Sum)
- 1898
- 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
- 1072
- Möbius Function
- 0
- Radical
- 538
- Omega Function (Ω)
- 4
- 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
- 32
- 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
- Numbers k such that phi(2k+1) < phi(2k).at n=27A001837
- Positions of remoteness 5 in Beans-Don't-Talk.at n=46A005697
- Number of directed site animals on hexagonal lattice.at n=12A006861
- Number of conjugacy classes in GL(n,3).at n=7A006952
- Coordination sequence T3 for Zeolite Code EMT.at n=38A008088
- Coordination sequence T3 for Zeolite Code LAU.at n=33A008126
- Coordination sequence T7 for Zeolite Code MTW.at n=30A008202
- a(n) = n OR n^2 (applied to ternary expansions).at n=45A008467
- a(n) = floor(n*(n - 1)*(n - 2)/32).at n=42A011914
- Start with 1, apply 1->12, 21->21, 22->21, 2->2 (for final 2); a(n) = length of n-th term.at n=23A013950
- Numbers k such that phi(k) + 9 | sigma(k + 9).at n=25A015788
- a(n) = Sum_{k=1..n} k*floor(n/k); also Sum_{k=1..n} sigma(k) where sigma(n) = sum of divisors of n (A000203).at n=50A024916
- 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 23.at n=12A031521
- Convolution of natural numbers n >= 1 with Lucas numbers L(k)(A000032) for k >= 2.at n=10A033811
- Zeckendorf expansion of n: repeatedly subtract the largest Fibonacci number you can until nothing remains. Big-endian concatenation of decimals.at n=28A035514
- Coordination sequence T6 for Zeolite Code STT.at n=31A038421
- a(n)=(s(n)+8)/10, where s(n)=n-th base 10 palindrome that starts with 2.at n=37A043081
- Numbers n such that string 1,5 occurs in the base 8 representation of n but not of n-1.at n=38A044200
- Numbers n such that string 5,0 occurs in the base 8 representation of n but not of n-1.at n=37A044227
- Numbers k such that the string 5,1 occurs in the base 9 representation of k but not of k-1.at n=29A044297