7900
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 16
- Digital Root
- 7
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 1
Divisibility
- Divisor Count
- 18
- Divisor Sum
- 17360
- Proper Divisor Sum (Aliquot Sum)
- 9460
- Abundant Number
- yes
- Perfect Number
- no
- Deficient Number
- no
- Highly Composite
- no
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 3120
- Möbius Function
- 0
- Radical
- 790
- Omega Function (Ω)
- 5
- 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
- no
- Narcissistic Number
- no
- Collatz Steps
- 39
- 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
- yes
- Odd
- no
Appears in sequences
- Triangle read by rows: T(n,k) = number of permutations of length n with exactly k rising or falling successions, for n >= 1, 0 <= k <= n-1.at n=51A001100
- Colored series-parallel networks.at n=5A001575
- Expansion of e.g.f. 1/(5 - exp(x) - exp(2*x) - exp(3*x) - exp(4*x)).at n=3A004702
- Iterated procedure 'composite k added to sum of its prime factors reaches a prime' yields 9 skipped primes.at n=43A050776
- Dimension of the space of weight n cuspidal newforms for Gamma_1( 91 ).at n=25A063364
- Positive square-root of terms of the self-convolution of A087150.at n=29A087151
- Numbers k such that numerator(Bernoulli(2*k)/(2*k)) is different from numerator(Bernoulli(2*k)/(2*k*(2*k-1))).at n=27A090495
- a(n) = prime(n)^1 + prime(n-1)^2 + prime(n-2)^3 + ... + prime(1)^n.at n=6A090831
- Number of non-isomorphic maximal independent sets of the n-cycle graph.at n=47A127685
- Numbers k such that absolute value of 9^k - k^9 is prime.at n=3A128449
- Numbers k such that k![7]-1 is prime (where k![7] = A114799(k) = septuple factorial).at n=51A156167
- A008585+A029907.at n=16A172050
- Numbers k such that Mordell's equation y^2 = x^3 - k has exactly 8 integral solutions.at n=36A179168
- Number of binary sequences of length n having a conjugate at Hamming distance 2.at n=24A179674
- Numbers k with equal remainders of (product of divisors of k) mod (sum of divisors of k) and (product of proper divisors of k) mod (sum of proper divisors of k).at n=25A192035
- Molecular topological indices of the cycle graphs.at n=24A192797
- Number of (n+1)X(n+1) 0..2 arrays with the maximum plus the upper median plus the lower median of every 2X2 subblock equal.at n=2A236876
- Number of (n+1) X (3+1) 0..2 arrays with the maximum plus the upper median plus the lower median of every 2 X 2 subblock equal.at n=2A236879
- T(n,k) = Number of (n+1) X (k+1) 0..2 arrays with the maximum plus the upper median plus the lower median of every 2 X 2 subblock equal.at n=12A236884
- Number of partitions of n such that (greatest part) + (least part) = number of parts.at n=48A237869