7975
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 28
- Digital Root
- 1
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 2
Divisibility
- Divisor Count
- 12
- Divisor Sum
- 11160
- Proper Divisor Sum (Aliquot Sum)
- 3185
- 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
- 5600
- Möbius Function
- 0
- Radical
- 1595
- 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
- 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
- no
- Achilles Number
- no
- Perfect Power
- no
- Smooth Number
- no
- Carmichael Number
- no
Classification
- Even
- no
- Odd
- yes
Appears in sequences
- a(n) = n*(19*n - 1)/2.at n=29A022276
- Expansion of Product_{m>0} (1+q^m)^(m(m+1)/2).at n=12A028377
- Denominators of continued fraction convergents to sqrt(433).at n=8A041825
- Number of ways to get ten-pin bowling score of 300-n.at n=43A079596
- a(n) = (10^k - n)(10^k + n), where k is the number of digits in n.at n=44A110397
- Partial sum of A005915.at n=9A126274
- Numbers k such that k divides 1 plus the sum of the first k primes.at n=13A128165
- Total number of nonprime parts in all partitions of n.at n=23A144119
- Triangle T(n,k) by rows: T(n, k) = (3*n-3*k+1)*T(n-1, k-1) +(3*k-2)*T(n-1, k) + 3*T(n-2, k-1) with T(n, 1) = T(n, n) = 1.at n=17A144440
- Triangle T(n,k) by rows: T(n, k) = (3*n-3*k+1)*T(n-1, k-1) +(3*k-2)*T(n-1, k) + 3*T(n-2, k-1) with T(n, 1) = T(n, n) = 1.at n=18A144440
- Number of lines through at least 2 points of a 6 X n grid of points.at n=31A160846
- The sum of all odd numbers from 2*n-1 to prime(n).at n=45A163637
- Numbers of the form 12n+7 for which Sum_{i=0..(4n+2)} J(i,12n+7) = 0, where J(i,m) is the Jacobi symbol.at n=23A165463
- Twin natural nonprimes with nonprime number of prime factors.at n=30A171995
- Numbers k such that Mordell's equation y^2 = x^3 - k has exactly 8 integral solutions.at n=37A179168
- The non-common part of the smaller number of an amicable pair.at n=12A180326
- Number of distinct solutions of Sum_{i=1..2} (x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1.at n=37A180773
- Unhappy numbers which enter the cycle (4, 16, 37, 58, 89, 145, 42, 20) at 20.at n=41A193572
- -5-Knödel numbers.at n=18A225509
- Start with 1. Successive digits in the sequence must differ by 2. Adjoin the smallest number not yet in the sequence.at n=35A228328