10989
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 18240
- Proper Divisor Sum (Aliquot Sum)
- 7251
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 6480
- Möbius Function
- 0
- Radical
- 1221
- Omega Function (Ω)
- 5
- 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
- no
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 68
- 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
- Numbers k such that 9*k = (k written backwards), k > 0.at n=1A001232
- Numbers k such that k written backwards is a nontrivial multiple of k.at n=2A008919
- Let j = | i - i_written_backwards |, k = j + j_written_backwards; then k is in this sequence.at n=43A008920
- Numbers k such that k and 9*k are anagrams.at n=6A023093
- Divisors of 999999.at n=50A027892
- Sort then Add, a(1) =9.at n=14A033896
- Sort then Add, a(1)=27.at n=12A033903
- a(n) = that n-digit number m which gives minimal integral value of m/(sum of digits of m); in case of a tie pick the smallest.at n=4A034727
- Erroneous version of A001232.at n=1A039684
- Nonpalindromic numbers k such that k is not divisible by 10 and k*R(k) is a square, where R(k) is the reversal of k (A004086).at n=18A062917
- Numbers k such that k*rev(k) is a square different from k^2, where rev=A004086, decimal reversal.at n=38A070760
- Binomial transform of A002487.at n=12A071014
- Non-palindromic numbers n, not divisible by 10, such that either n divides R(n) or R(n) divides n, where R(n) is the digit-reversal of n.at n=4A071685
- Non-palindromic numbers such that either x=q1.Rev[x] or Rev[x]=q2.x, where R[x]=A004086[x] and q1 or q2 are integers not divisible by 10.at n=16A071687
- Numbers n for which there are exactly nine k such that n = k + reverse(k).at n=29A072433
- Numbers k such that all the following properties hold: (i) k*reverse(k) is a square; (ii) k != reverse(k); (iii) k and reverse(k) are not both squares; and (iv) k and reverse(k) have the same number of digits.at n=10A082994
- Numbers which are sums of two and also sums of three positive cubes.at n=23A085336
- Numbers which are sums of two, three and four cubes.at n=13A085337
- Numbers which are sums of two, three, four and also sums of five cubes.at n=12A085338
- Largest member of the n-th row of the triangular triangle (A093445).at n=37A093446