7923
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 21
- Digital Root
- 3
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 5
Divisibility
- Divisor Count
- 8
- Divisor Sum
- 11200
- Proper Divisor Sum (Aliquot Sum)
- 3277
- 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
- 4968
- Möbius Function
- -1
- Radical
- 7923
- Omega Function (Ω)
- 3
- 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
- 52
- 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
- no
- Odd
- yes
Appears in sequences
- Number of partitions into non-integral powers.at n=35A000327
- 10-gonal (or decagonal) pyramidal numbers: a(n) = n*(n + 1)*(8*n - 5)/6.at n=18A007585
- Number of segments (and sides) created by diagonals of an n-gon in general position.at n=16A014628
- a(n) = n*(11*n - 1)/2.at n=38A022268
- Number of terms in 5th derivative of a function composed with itself n times.at n=17A022815
- a(n) = 1*t(n) + 2*t(n-1) + ... + k*t(n+1-k), where k=floor((n+1)/2) and t(n)=2*n+1 (odd numbers).at n=34A023865
- Distinct odd elements in 4-Pascal triangle A028275 (by row).at n=32A028281
- Odd elements (greater than 1) to right of central elements in 4-Pascal triangle A028275.at n=32A028287
- 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 89.at n=0A031587
- Numbers k such that the least term in the periodic part of the continued fraction for sqrt(k) is 89.at n=0A031767
- Numbers k such that 239*2^k+1 is prime.at n=22A032496
- Number of partitions of n into parts not of form 4k+2, 16k, 16k+7 or 16k-7.at n=50A036023
- Numerators of continued fraction convergents to sqrt(317).at n=7A041598
- p^2 + 2 where p is a prime.at n=23A061725
- Number of length 3 walks on an n-dimensional hypercubic lattice starting at the origin and staying in the nonnegative part.at n=19A064043
- Numbers k such that the digits of k joined to the digits of 2k contain each of the digits from 1 to 9 once.at n=7A064160
- a(n) = floor(1/(n-1) * Sum_{k=1..n-1} a(k)^(n/k)), given a(0)=1, a(1)=2, a(2)=5.at n=12A079117
- Numbers k such that (2*k)!/k! + 1 is prime.at n=13A112855
- Approximation to the (10^n)-th prime by applying a bisection to Gram's formula for Riemann's approximation of the prime counting function.at n=2A121046
- Odd interprimes divisible by 19.at n=19A126231