9890
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 26
- Digital Root
- 8
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 19008
- Proper Divisor Sum (Aliquot Sum)
- 9118
- 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
- 3696
- Möbius Function
- 1
- Radical
- 9890
- 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
- yes
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 122
- 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
- Number of non-stereoisomeric paraffins with n carbon atoms.at n=20A000627
- a(n) = (3*n - 1)*(4*n - 1).at n=29A033578
- Maximal value of Sum_{i=1..n} (p(i) - p(i+1))^2, where p(n+1) = p(1), as p ranges over all permutations of {1, 2, ..., n}.at n=30A064842
- a(n) = smallest non-palindromic number k such that k and its digit reversal are divisible by n, or 0 if n is a multiple of 10.at n=42A069555
- a(n) = n*(n^2+3*n-1)/3.at n=30A084990
- Triangle T(n,k), 0<= k <= n, read by rows; given by [0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, ...] DELTA [1, 0, 2, 1, 3, 2, 4, 3, 5, 4, 6, 5, ...] where DELTA is the operator defined in A084938.at n=31A094344
- a(n+1) = a(n) + (if a(n) is odd then (next odd square) else (next even square)), a(0) = 1.at n=20A116955
- a(n) = p(n)*p(n+2)-p(n+1), where p(n) is the n-th prime.at n=24A152530
- Triangle T(n, k, q) = Sum_{j=0..10} q^j * floor( binomial(n+1,k)*binomial(n-1,k-1)/(2^j*(n+1)) ) for q = 1, read by rows.at n=58A174043
- Triangle T(n, k, q) = Sum_{j=0..10} q^j * floor( binomial(n+1,k)*binomial(n-1,k-1)/(2^j*(n+1)) ) for q = 1, read by rows.at n=62A174043
- Number of ways to arrange 5 nonattacking queens on the lower triangle of an n X n board.at n=9A194495
- Numbers k such that 2*(3^k-2*k)+1 is prime.at n=11A195815
- a(n) = n*(5*n^2 - 3*n + 4) / 6.at n=23A203552
- Numbers k such that 1 + k + k^3 + k^5 + k^7 + k^9 + ... + k^45 is prime.at n=39A244387
- G.f.: Sum_{k>=1} x^k/(1+x^k) * Product_{k>=1} (1+x^k)/(1-x^k).at n=19A305101
- Number of compositions (ordered partitions) of n into odd primes (including 1).at n=21A309676
- Number of antichains of multisets with multiset-join a normal multiset of size n.at n=5A317073
- Number of compositions of n with equal circular differences up to sign.at n=46A325558
- The lower (or left) offset of a 196-iterate (A006960) from the largest palindrome less than the iterate.at n=15A331556
- Composite integers m such that A003500(m) == 4 (mod m).at n=38A335673