17831
domain: N
Properties
Digital Properties
- Digit Count
- 5
- Digit Sum
- 20
- Digital Root
- 2
- Palindromic Number
- no
- Repdigit
- no
- Automorphic
- no
- Kaprekar Number
- no
- Multiplicative Persistence
- 4
Divisibility
- Divisor Count
- 4
- Divisor Sum
- 19464
- Proper Divisor Sum (Aliquot Sum)
- 1633
- Abundant Number
- no
- Perfect Number
- no
- Deficient Number
- yes
- Weird Number
- no
- Untouchable Number
- no
- Primitive Abundant
- no
Derived Values
- Euler's Totient
- 16200
- Möbius Function
- 1
- Radical
- 17831
- 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
- 53
- 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
- Numbers that are the sum of 2 positive 5th powers.at n=24A003347
- Numbers that are the sum of at most 2 positive 5th powers.at n=32A004842
- a(n) = 4^n + 7^n.at n=5A074613
- Numbers of form x^5 + y^5, x,y > 0 and x <> y.at n=18A088703
- Numerators of coefficients in g.f. that satisfies: [x^n] A(x)^(1/n) = 0 for all n>1, with a(0)=a(1)=1.at n=5A107100
- Number of decimal digits in (10^n)!!.at n=4A114488
- a(n) = least k such that the remainder when 28^k is divided by k is n.at n=38A128368
- Number of strings of numbers x(i=1..5) in 0..n with sum i^2*x(i) equal to n*25.at n=24A183956
- G.f.: exp( Sum_{n>=1} (x^n/n) * Product_{d|n} (1 + d*x^n) ).at n=40A205478
- Nonprime numbers with all divisors starting and ending with digit 1.at n=36A208261
- Number of n X 2 arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, with every occupancy equal to zero or two.at n=9A221304
- T(n,k)=Number of nXk arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, with every occupancy equal to zero or two.at n=56A221308
- Numbers of the form 4^j + 7^k, for j and k >= 0.at n=43A226817
- Numbers that are sums of two coprime positive fifth powers.at n=15A228542
- Integers n of the form 8k+7 that are sum of distinct squares of the form m, m+1, m+2, m+4, where m == 1 (mod 4).at n=16A243578
- Numbers k such that k!6 - 8 is prime, where k!6 is the sextuple factorial number (A085158).at n=42A289686
- Replacing each digit d in decimal expansion of n with d^2 yields a prime at each step when done recursively three times.at n=22A316604
- Nonprime numbers k for which k*k' is a palindrome, where k' is the arithmetic derivative of k (A003415).at n=16A359331
- Number of integer partitions of n such that it is not possible to choose a different prime factor of each part.at n=36A370593
- Expansion of Sum_{1<=i<=j<=k<=l} q^(i+j+k+l)/( (1-q^i)*(1-q^j)*(1-q^k)*(1-q^l) )^2.at n=9A374931