7475
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 23
- Digital Root
- 5
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 10416
- Proper Divisor Sum (Aliquot Sum)
- 2941
- 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
- 5280
- Möbius Function
- 0
- Radical
- 1495
- Omega Function (Ω)
- 4
- 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
- yes
- Harshad Number
- yes
- Narcissistic Number
- no
- Collatz Steps
- 101
- 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
- Number of n-step walks on square lattice in the first quadrant which finish at distance n-3 from the x-axis.at n=22A005564
- Expansion of Product_{k>=1} (1-x^k)^26.at n=4A010831
- Pair up the numbers.at n=37A030656
- Numbers whose base-3 representation has exactly 9 runs.at n=23A043589
- Numbers n such that number of runs in the base 3 representation of n is congruent to 1 mod 8.at n=39A043799
- Numbers n such that number of runs in the base 3 representation of n is congruent to 0 mod 9.at n=23A043806
- Numbers k such that number of runs in the base 3 representation of k is congruent to 9 mod 10.at n=23A043824
- Numbers n such that 159*2^n-1 is prime.at n=20A050831
- a(n) = Sum_{d|n} d*prime(d).at n=37A061150
- z-value of the solution (x,y,z) to 3/(2n+1) = 1/x + 1/y + 1/z satisfying 0 < x < y < z, odd x, y, z and having the largest z-value. The x and y components are in A075260 and A075261.at n=32A075262
- Numbers k such that (k!)^2 + k! - 1 is prime.at n=12A084830
- Numbers n such that 2*n*k(n) is rational but not an integer, where k(n) is sum of successive remainders when computing the Euclidean algorithm for (1, 1/sqrt(n)) as defined in A086378 (MuPAD program is given there); numbers belonging to A086378 but not to A088900.at n=8A087414
- Numbers k such that the k-th and (k+1)-th primes have the same sum of squares of digits.at n=29A109182
- Positive integers i for which A112049(i) == 8.at n=7A112068
- Height of the last peak summed over all skew Dyck paths of semilength n.at n=6A128746
- Odd composite numbers such that the sum of any two terms, plus 1, is composite.at n=34A133763
- Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1001-1111 pattern in any orientation.at n=16A146622
- a(n) = (11*n^2 + 19*n + 10)/2.at n=36A160749
- Number of digits in n-th even perfect number written in base 8.at n=22A161514
- a(n) = n*(7*n+3)/2.at n=46A186029