7423
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
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 8008
- Proper Divisor Sum (Aliquot Sum)
- 585
- 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
- 6840
- Möbius Function
- 1
- Radical
- 7423
- Omega Function (Ω)
- 2
- Little Omega Function (ω)
- 2
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
- 238
- Smith Number
- no
- Vampire Number
- no
Primality
- Prime
- no
- Composite Number
- yes
- Semiprime
- yes
- 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
- no
- Odd
- yes
Appears in sequences
- Number of solutions to c(1)*prime(2) +...+ c(n)*prime(n+1) = 0, where c(i) = +-1 for i > 1, c(1) = 1.at n=21A022897
- Super-4 Numbers (4 * n^4 contains substring '4444' in its decimal expansion).at n=2A032744
- Sums of 11 distinct powers of 2.at n=33A038462
- Partition numbers rounded to nearest integer given by the Hardy-Ramanujan approximate formula.at n=30A050811
- Composite numbers k for which phi(k) + sigma(k) is an integer multiple of the 4th power of the number of divisors of k.at n=32A055468
- Björner-Welker sequence: 2^n*(n^2 + n + 2) - 1.at n=7A055580
- McKay-Thompson series of class 42b for Monster.at n=46A058676
- (1-2*cos(1/11*Pi))^n+(1+2*cos(2/11*Pi))^n+(1-2*cos(3/11*Pi))^n+(1+2*cos(4/11*Pi))^n+(1-2*cos(5/11*Pi))^n.at n=8A062883
- Number of unlabeled and connected graphs which are weakly chordal. (G is weakly chordal iff there are no induced cycles of size 5 or more in G nor in its complement.)at n=7A079457
- a(n) = least odd number such that all pairwise sums a(i) + a(j), i < j <= n, are distinct.at n=46A080430
- a(n) is the number of times that sums 3 +- 5 +- 7 +- 11 +- ... +- prime(2n+1) of the first 2n odd primes is zero. There are 2^(2n-1) choices for the sign patterns.at n=10A083309
- Numbers k such that sigma(phi(k))-phi(sigma(k)) is nonzero and divisible by phi(k), that is A065395(k)/A000010(k) is a nonzero integer.at n=37A092587
- Expansion of 1/sqrt((1-x)^2 - 4*x^4).at n=16A098482
- Triangle T(n,k) read by rows: number of Green's R-classes in the semigroup of order-preserving partial transformations (of an n-element chain) consisting of elements of height k (height(alpha) = |Im(alpha)|).at n=58A112857
- Triangle read by rows: T(n,0) = T(n,n) = 1 and for 0<k<n: T(n,k) = 2*T(n-1, k-1) + T(n-1,k).at n=62A119258
- Partial sums of skinny numbers (A061909).at n=38A130596
- A sequence of asymptotic density zeta(9) - 1, where zeta is the Riemann zeta function.at n=14A143035
- 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, 0, 0), (-1, 1, 1), (1, -1, 1), (1, 0, 0), (1, 1, -1)}.at n=8A148750
- a(n) = 256*n - 1.at n=28A158250
- Numbers k such that 3 + 10^k + 3*100^k is prime.at n=11A171149