7803
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 18
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 12280
- Proper Divisor Sum (Aliquot Sum)
- 4477
- 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
- 4896
- Möbius Function
- 0
- Radical
- 51
- Omega Function (Ω)
- 5
- 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
- 145
- 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
- yes
- Achilles Number
- yes
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- Number of partitions of n in which no parts are multiples of 3.at n=42A000726
- Bisection of A001400.at n=49A014125
- a(n) = (2*n - 7)*n^2.at n=17A015242
- 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 87.at n=22A031585
- Number of partitions of n into parts not of the form 19k, 19k+6 or 19k-6. Also number of partitions with at most 5 parts of size 1 and differences between parts at distance 8 are greater than 1.at n=33A035975
- T(n,n-4), array T as in A038792.at n=21A038794
- a(n) = a(n-1) + a(m) for n >= 4, where m = 2^(p+1) + 2 - n and p is the unique integer such that 2^p < n - 1 <= 2^(p+1), starting with a(1) = 1 and a(2) = a(3) = 3.at n=44A050065
- Numbers n such that n | 11^n + 10^n + 9^n + 8^n + 7^n + 6^n.at n=22A057258
- Partial sums of n 3-spaced triangular numbers beginning with t(2), e.g., a(2) = t(2) + t(5) = 3 + 15 = 18.at n=16A085789
- Final terms of rows of A085612.at n=21A085836
- Numbers that factorize into a prime number of distinct prime factors each raised to a different prime exponent.at n=35A114128
- Triangle read by rows: T(n,k) is the number of Motzkin paths of length n having k UDH's starting at level 0 (U=(1,1),H=(1,0),D=(1,-1)).at n=47A114581
- Both n and the reverse of n are powerful(1) numbers (A001694).at n=28A115656
- Powerful(1) numbers (A001694) whose digit reversal is the product of 2 palindromes greater than 1.at n=35A115697
- Start with 1027 and repeatedly reverse the digits and add 16 to get the next term.at n=32A119455
- Numbers (excluding primes and powers of primes) such that the square mean of their prime factors is a prime (where the square mean of c and d is sqrt((c^2+d^2)/2)).at n=35A134604
- Numbers of the form p^2 * q^3, where p,q are distinct primes.at n=21A143610
- Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1111-0010-0010 pattern in any orientation.at n=16A147174
- Number of walks within N^3 (the first octant of Z^3) starting at (0,0,0) and consisting of n steps taken from {(-1, 0, 1), (0, -1, 1), (0, 1, -1), (1, 0, 0), (1, 0, 1)}.at n=7A150488
- a(n) = 9*n^2 - 10*n + 3.at n=30A154262