7248
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
- 4
Divisibility
- Divisor Count
- 20
- Divisor Sum
- 18848
- Proper Divisor Sum (Aliquot Sum)
- 11600
- 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
- 2400
- Möbius Function
- 0
- Radical
- 906
- Omega Function (Ω)
- 6
- 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
- 18
- 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 lines through exactly 2 points of an n X n grid of points.at n=14A018809
- Numbers whose set of base-15 digits is {2,3}.at n=17A032815
- Every run of digits of n in base 15 has length 2.at n=30A033013
- Positive integers with more base-15 runs of even length than odd.at n=32A044841
- Open 3-dimensional ball numbers (version 3): a(n) is the number of integer points (i,j,k) contained in an open ball of diameter n, centered at (1/2,1/2,0).at n=24A053595
- Numbers k such that k^12 == 1 (mod 13^3).at n=39A056086
- Triangle of coefficients of polynomials used for g.f.s of columns of A067304.at n=42A067329
- Numbers k such that phi(k) = bigomega(k)*tau(k)^2.at n=14A068540
- A Wallis pair (x,y) satisfies sigma(x^2) = sigma(y^2); sequence gives x's for indecomposable Wallis pairs with x < y (ordered by values of x).at n=22A075768
- Numbers n such that zero is never reached by iterating the mapping k -> abs(reverse(lpd(k))-reverse(gpf(k))). lpd(k) is the largest proper divisor and gpf(k) is the largest prime factor of k.at n=17A076425
- Numbers n with property that n is not a power of 2 and the finite sequence n, f(n), f(f(n)), ...., 1 in the Collatz (or 3x + 1) problem contains exactly one prime. (The earliest "1" is meant.)at n=34A078440
- Integers that occur more than once as the difference of the squares of two consecutive primes.at n=31A078667
- Numbers that can be expressed as the difference of the squares of primes in just three distinct ways.at n=24A090782
- Numbers that can be expressed as the difference of the squares of consecutive primes in just two distinct ways.at n=28A090784
- a(n) is the largest number such that all of a(n)'s length-n substrings are distinct and divisible by 24.at n=1A093224
- Numbers n such that the sum of the first n primes is divisible by n + 1.at n=11A098074
- Least positive k such that k * [RSA-200]^n - 1 is prime, where RSA-200 is the 200 decimal digit RSA challenge number A391940(15).at n=15A108375
- Triangle read by rows: T(n,k) is the number of Motzkin paths of length n having k UDH's starting at level 0 (U=(1,1),H=(1,0),D=(1,-1)).at n=36A114581
- n times n+3 gives the concatenation of two numbers m and m-7.at n=1A116241
- Number of partitions of n into parts that are odd or == +- 2 (mod 10).at n=39A133153