7575
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 24
- Digital Root
- 6
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 3
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 12648
- Proper Divisor Sum (Aliquot Sum)
- 5073
- 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
- 4000
- Möbius Function
- 0
- Radical
- 1515
- 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
- no
- Harshad Number
- no
- Narcissistic Number
- no
- Collatz Steps
- 83
- 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
- Self-convolution of array T given by A008288.at n=6A026933
- 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 29.at n=27A031527
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 29.at n=2A031707
- Lucky numbers that are concatenations of a number k with itself.at n=8A032650
- Number of partitions of n into parts not of form 4k+2, 24k, 24k+5 or 24k-5. Also number of partitions in which no odd part is repeated, with at most 2 parts of size less than or equal to 2 and where differences between parts at distance 5 are greater than 1 when the smallest part is odd and greater than 2 when the smallest part is even.at n=47A036031
- Number of partitions satisfying cn(2,5) + cn(3,5) <= cn(0,5) + cn(1,5) and cn(2,5) + cn(3,5) <= cn(0,5) + cn(4,5).at n=37A039865
- Odd numbers with exactly 4 palindromic prime factors (counted with multiplicity).at n=42A046374
- Number of n-crossing hyperbolic knots having symmetry group D1.at n=13A052415
- Moebius invariant of cographic hyperplane arrangement for complete graph K_n. Also value of Tutte dichromatic polynomial T_G(0,1) for G=K_n. Also alternating sum F_{n,1} - F_{n,2} + F_{n,3} - ..., where F_{n,k} is the number of labeled forests on n nodes with k connected components.at n=6A057817
- Write 1, 2, 3, 4, ... counterclockwise in a hexagonal spiral around 0 starting left down, then a(n) is the sequence found by reading from 0 in the vertical upward direction.at n=25A063436
- 1/n has period 4 in base 10.at n=32A069858
- Number of squares on infinite half chessboard at <=n knight moves from a fixed point on the diagonal.at n=33A098499
- Number of distinct products i*j*k*l for 1 <= i < j < k < l <= n.at n=30A100438
- Number of positive integers <= 10^n that are divisible by no prime exceeding 7.at n=10A106600
- Difference between two consecutive squares enclosing 3^(2n+1).at n=7A119901
- The first 8 values are predefined, the remaining set to a(n) = 48*prime(n)+n+2.at n=36A129025
- Number of n X n binary arrays with all ones connected only in a 0100-1100-0111 pattern in any orientation.at n=6A146578
- Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-1100-0111 pattern in any orientation.at n=15A146580
- Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 0100-1100-0111 pattern in any orientation.at n=14A146580
- 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, -1, 0), (-1, 1, -1), (0, 0, 1), (0, 1, 0), (1, 0, 0)}.at n=7A151036