7990
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 25
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 16
- Divisor Sum
- 15552
- Proper Divisor Sum (Aliquot Sum)
- 7562
- 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
- 2944
- Möbius Function
- 1
- Radical
- 7990
- 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
- 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
- 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
- Oscillates under partition transform.at n=48A007210
- "CGK" (necklace, element, unlabeled) transform of 1,2,3,4,...at n=14A032158
- Row sums of convolution triangle A030524.at n=5A043553
- Number of partitions of n with equal number of parts congruent to each of 0, 2 and 3 (mod 4).at n=54A046768
- Partial sums of rows of A047884. Young Tableaux by height.at n=49A049400
- Number of Young tableaux of height <= 5.at n=10A049401
- Numbers k such that Cyclotomic(k,k) (i.e., the value of k-th cyclotomic polynomial at k) is a prime number.at n=25A070519
- Expansion of 1/((1-x)*(1+x+x^2+2*x^3)).at n=34A077909
- Third partial sums of fifth powers (A000584).at n=4A101099
- Triangle T, read by rows, equal to the matrix square of triangle A117418; also equals a column bisection of triangle A117418: column 2k+1 of T^(1/2) equals column k of T.at n=39A117427
- a(n) = (n-1)*(n+2)*(2*n+11)/2.at n=17A130862
- a(n) = 250*n - 10.at n=31A154378
- Number of Dyck paths with no UUU's and no DDD's, of semilength n and having no UDUD's (U=(1,1), D=(1,-1)).at n=19A166289
- a(n) = a(n-1) + A073053(a(n-1)).at n=35A173578
- Number of nondecreasing arrangements of 5 nonzero numbers in -(n+3)..(n+3) with sum zero.at n=13A188335
- 20k^2-40k+10 interleaved with 20k^2-20k+10 for k>=0.at n=42A216875
- a(n) = (binomial(2n, n) - 2) mod n^3.at n=21A246133
- a(n) = 3*4^n + 10*2^n + 6*3^n + 5^n + 15.at n=5A254364
- a(0)=1, then a(n) is the least sum of two successive primes that is a multiple of n and > a(n-1).at n=47A260966
- Breadth-first traversal of a binary tree in which the value at the n-th node is equal to ParentNode()*prime(n-1).at n=15A268878