7488
domain: N
Properties
Digital Properties
- Digit Count
- 4
- Digit Sum
- 27
- Digital Root
- 9
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 42
- Divisor Sum
- 23114
- Proper Divisor Sum (Aliquot Sum)
- 15626
- 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
- 2304
- Möbius Function
- 0
- Radical
- 78
- Omega Function (Ω)
- 9
- 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
- 26
- 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
- Number of permutations of length n by rises.at n=4A000544
- Discriminants of totally real quartic fields (see comments).at n=25A002769
- Irregular triangle read by rows: T(n,k) (n >= 1, 0 <= k <= [n/2]) = number of permutations of 1..n with [n/2]-k runs of consecutive pairs up and down (divided by 2).at n=21A010030
- Smallest positive number that can be written as sum of distinct Fibonacci numbers in n ways.at n=74A013583
- Discriminants of totally real quartic fields.at n=32A023680
- Number of products of distinct primes <= prime(n) equal to -1 (mod prime(n)).at n=19A024404
- n written in fractional base 10/7.at n=48A024662
- 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 43.at n=18A031541
- a(n) = floor( n(n+1)(n+2)(n+3)(n+4) / (n+(n+1)+(n+2)+(n+3)+(n+4)) ).at n=12A032768
- Integer quotients of n(n + 1)(n + 2)(n + 3)(n + 4) / (n+(n+1)+(n+2)+(n+3)+(n+4)).at n=10A032770
- Positive integers of the form n(n+1)(n+2)(n+3)(n+4)/(n+(n+1)+(n+2)+(n+3)+(n+4)) that are a multiple of n.at n=7A032794
- Numbers each of whose runs of digits in base 12 has length 2.at n=44A033010
- Numbers that are divisible by 6 (and 18) and are differences between two cubes in at least one way.at n=25A038852
- Numbers ending with '8' that are the difference of two positive cubes.at n=28A038863
- a(1) = 1, a(m+1) = 2*Sum_{k=1..floor((m+1)/2)} a(m+1-k).at n=9A039721
- Numbers that are divisible by exactly 9 primes with multiplicity.at n=34A046312
- Numbers n such that A048767(n) = n.at n=24A048768
- Octahedral torus number: a(n) = n^2 + 2*(Sum_{k=1..n-1} k^2) - 2*(floor((n+1)/2)^2 + 2*(Sum_{k=1..floor((n+1)/2)-1} k^2)) + (1 - (-1)^n)/2.at n=24A050442
- Totient(n) and cototient(n) are squares.at n=33A054754
- Numbers k such that phi(k) and cototient(k) are squares but k is not in A054755.at n=8A054756